Elastomeric compositions

ABSTRACT

The present invention includes compositions suitable for air barriers such as innerliners where adhesion to tire carcass materials (e.g., SBR) and flexibility are desirable, as well as low air permeability. The invention includes a tire innerliner made by combining a filler; a sulfur cure system; optionally at least one secondary rubber; and at least one halogenated terpolymer of C 4  to C 8  isoolefin derived units, C 4  to C 14  multiolefin drived units, and p-alkylstyrene derived units. Examples of suitable fillers include modified carbon black, carbon black, silica, exfoliated clays, and combinations thereof. The present invention also includes a method of producing an elastomeric terpolymer composition comprising combining in a diluent C 4  to C 8  isoolefin monomers, C 4  to C 14  multiolefin monomers, and p-alkylstyrene monomers in the presence of a Lewis acid and at least one initiator to produce the terpolymer. Examples of suitable initiators include cumyl compounds and or halogenated organic compounds, especially secondary or tertiary halogenated compounds such as, for example, t-butylchloride, 2-acetyl-2-phenylpropane (cumyl acetate), 2-methoxy-2-phenyl propane (cumylmethyl-ether), 1,4-di(2-methoxy-2-propyl)benzene (di(cumylmethyl ether)); the cumyl halides, particularly the chlorides, such as, for example 2-chloro-2-phenylpropane, cumyl chloride (1-chloro-1-methylethyl)benzene), 1,4-di(2-chloro-2-propyl)benzene (di(cumylchloride)), and 1,3,5-tri(2-chloro-2-propyl)benzene (tri(cumylchloride)); the aliphatic halides, particularly the chlorides, such as, for example, 2-chloro-2,4,4-trimethylpentane (TMPCl), and 2-bromo-2,4,4-trimethylpentane (TMPBr).

FIELD OF INVENTION.

[0001] The present invention relates to compositions ofisobutylene-based terpolymers. More particularly, the invention relatesto terpolymer compositions, wherein the terpolymer includes isoolefinderived units, styrenic derived units, and multiolefin derived units,the compositions being useful in tires, particularly in automotivecomponents such as treads, belts, tire innerliners, innertubes, andother air barriers.

BACKGROUND OF THE INVENTION

[0002] Isobutylene-based terpolymers including isoolefin, styrenic, andmultiolefin derived units have been disclosed in U.S. Pat. No.3,948,868, U.S. Pat. No. 4,779,657; and WO 01/21672. Compositions usefulfor air barriers such as innerliners and innertubes which include suchterpolymers are not known.

[0003] Improving the specific properties of tire innerliners withoutsacrificing current performance is desirable. Use of isobutylene-basedelastomers such as butyl rubber (IIR), halobutyl rubbers (chloro (CIIR)or bromo (BIIR)) or brominated isobutylene-co-p-methylstyrene (BIMS) asthe innerliner polymer serves to provide for decreased permeability toair compared to general purpose elastomers (such as NR, BR, or SBR) ortheir blends with isobutylene elastomers. Flex fatigue resistance,adhesion to other tire components such as carcass and bead compounds,and abrasion resistance are also desirable performance properties. Useof BIMS copolymers increases the compatibility of the innerliner withGPR hydrocarbon elastomers; however, co-vulcanization using sulfur curesystems is still not achieved to a sufficiently high degree. Improvedlab adhesion values to carcass compounds is still desirable.

[0004] To be useful in, for example, a tire tread or tire sidewall aspart of a multi-component automobile tire, the terpolymer must desirablybe both sulfur curable, and compatible with other rubbers such asnatural rubber and polybutadiene. Further, in order to serve as an airbarrier such as a tire innerliner, the terpolymer compositions must beair impermeable, adhere well to the tire carcass such as apoly(styrene-co-butadiene) (SBR) carcass, and have suitable durability.These properties are often difficult to achieve together, as improvingone can often diminish the other.

[0005] It is unexpected that the incorporation of a multiolefin derivedunit in a composition including a polymer having aisobutylene/p-methylstyrene backbone would contribute to both improvedcarcass adhesion and flexibility, while maintaining air impermeability.Likewise, it is unexpected that such terpolymer will sulfur cure inlight of the IB/PMS copolymers failing to sulfur vulcanize. Yet, theinventors here demonstrate, among other things, the practical use ofcertain isoolefinic terpolymers that incorporate multiolefins that aresulfur curable. More particularly, it has been discovered that theseterpolymers are useful in curable blends with suitable fillers and thelike due to improved traction and abrasion performance, thus makingthese compositions useful in tire treads, sidewalls as well as airbarriers such as innerliners and innertubes for pneumatic tires.

[0006] Other background references include U.S. Pat. Nos. 3,560,458 and5,556,907 and EP 1 215 241 A.

SUMMARY OF THE INVENTION

[0007] These and other problems are solved by a terpolymer prepared byincorporating isobutylene (IB) along with isoprene (I) andpara-methylstyrene (MS) derived units. The isoprene is desirably presentin sufficient concentration in the terpolymer to promote vulcanizationby conventional sulfur curing ingredients. In addition, the terpolymercan be halogenated to further enhance crosslinking reactions. Thus,halogen atoms, desirably chlorine or bromine, can be incorporated ontothe isoprene moiety in the backbone of the terpolymer such as inbromobutyl rubber, or onto the backbone and the methyl group of themethylstyrene. These reactive sites can allow for crosslinking of thehalogenated terpolymer with itself, and also with hydrocarbon dienerubbers used in tire carcass compounds, such as NR, BR and SBR.

[0008] The present invention includes compositions suitable for airbarriers such as innerliners or innertubes for automobile tires andother articles where air impermeability and flexibility are desirable.The invention includes an automotive innerliner made from a compositionof at least one (i.e., one or more) filler; a sulfur cure system; andoptionally at least one secondary rubber; and at least one halogenatedterpolymer of C₄ to C₈ isoolefin derived units, C₄ to C₁₄ multiolefinderived units, and p-alkylstyrene derived units. In one embodiment, theterpolymer is halogenated. Examples of suitable fillers include but arenot limited to carbon black, modified carbon black, silica, so callednanoclays or exfoliated clays, and combinations thereof.

[0009] The present invention also includes a method of producing anelastomeric terpolymer composition comprising combining in a diluenthaving a dielectric constant of at least 6 in one embodiment, and atleast 9 in another embodiment: C₄ to C₈ isoolefin monomers, C₄ to C₁₄multiolefin monomers, and p-alkylstyrene monomers in the presence of aLewis acid and at least one initiator to produce the terpolymer.Examples of suitable initiators include t-butylchloride,2-acetyl-2-phenylproparie (cumyl acetate), 2-methoxy-2-phenyl propane(cumylmethyl-ether), 1,4-di(2-methoxy-2-propyl)benzene (di(cumylmethylether)); the cumyl halides, particularly the chlorides, such as, forexample 2-chloro-2-phenylpropane, cumyl chloride(1-chloro-1-methylethyl)benzene), 1,4-di(2-chloro-2-propyl)benzene(di(cumylchloride)), and 1,3,5-tri(2-chloro-2-propyl)benzene(tri(cumylchloride)); the aliphatic halides, particularly the chlorides,such as, for example, 2-chloro-2,4,4-trimethylpentane (TMPCl),2-bromo-2,4,4-trimethylpentane (TMPBr), and2,6-dichloro-2,4,4,6-tetramethylheptane; cumyl and aliphatic hydroxylssuch as 1,4-di((2-hydroxyl-2-propyl)-benzene),2,6-dihydroxyl-2,4,4,6-tetramethyl-heptane, 1-chloroadamantane and1-chlorobomane, 5-tert-butyl-1,3-di(1-chloro-1-methyl ethyl) benzene andsimilar compounds or mixtures of such compounds as listed above.

BRIEF DESCRIPTION OF DRAWING

[0010]FIG. 1 is a plot of tangent delta (G″/G′) values as a function oftemperature for example 4 (SBB), 5 (BIIR), 6 (BIMS) and 7 (BrIBIMS), allincluding in the composition carbon black.

DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention includes a method of makingisobutylene-based terpolymers including isobutylene derived units,styrenic derived units, and multiolefin derived units, and compositionsof these terpolymers and halogenated terpolymers. The terpolymers of thepresent invention can be made via carbocationic polymerization processesusing a mixture of at least the monomers, a Lewis acid catalyst, aninitiator, and a diluent. The polymerization is typically carried outeither in slurry such as in a continuous slurry reactor or butyl-typereactor, or in solution. The copolymerization reactor is maintainedsubstantially free of impurities which can complex with the catalyst,the initiator, or the monomers. By substantially free of impurities, itis meant that the impurities are at a level of no greater than 100 ppm.Anhydrous conditions are preferred and reactive impurities, such ascomponents containing active hydrogen atoms (water, alcohol and thelike) are desirably removed from both the monomer and diluents bytechniques well-known in the art. These impurities, such as water, arepresent, if at all, to an extent no greater than 500 ppm in oneembodiment.

[0012] As used herein, the term “catalyst system” refers to and includesany Lewis Acid or other metal complex used to activate thepolymerization of olefinic monomers, as well as the initiator describedbelow, and other minor catalyst components described herein.

[0013] As used herein, the term “polymerization system” includes atleast the catalyst system, diluent, the monomers and reacted monomers(polymer) within the butyl-type reactor. A “butyl-type” reactor refersto any suitable reactor such as a small, laboratory scale, batch reactoror a large plant scale reactor. One embodiment of such a reactor is acontinuous flow stirred tank reactor (“CFSTR”) is found in U.S. Pat. No.5,417,930. In these reactors, slurry (reacted monomers) is circulatedthrough tubes of a heat exchanger by a pump, while boiling ethylene onthe shell side provides cooling, the slurry temperature being determinedby the boiling ethylene temperature, the required heat flux and theoverall resistance to heat transfer.

[0014] As used herein, the term “diluent” means one or a mixture of twoor more substances that are liquid or gas at room temperature andatmospheric pressure that can act as a reaction medium forpolymerization reactions.

[0015] As used herein, the term “slurry” refers to reacted monomers thathave polymerized to a stage that they have precipitated from thediluent. The slurry “concentration” is the weight percent of thesereacted monomers—the weight percent of the reacted monomers by totalweight of the slurry, diluent, unreacted monomers, and catalyst system.

[0016] The term “elastomer” may be used interchangeably with the terms“rubber”, as used herein, and is consistent with the definition in ASTM1566.

[0017] As used herein, the new numbering scheme for the Periodic TableGroups are used as in HAWLEY'S CONDENSED CHEMICAL DICTIONARY 852 (13thed. 1997).

[0018] As described herein, polymers and copolymers of monomers arereferred to as polymers or copolymers including or comprising thecorresponding monomer “derived units”. Thus, for example, a copolymerformed by the polymerization of isoprene and isobutylene monomers may bereferred to as a copolymer of isoprene derived units and isobutylenederived units.

[0019] As used herein the term “butyl rubber” is defined to mean apolymer predominately comprised of repeat units derived from isoolefinssuch as isobutylene but including repeat units derived from amultiolefin such as isoprene; and the term “terpolymer” is used todescribe a polymer including isoolefin derived units, multiolefinderived units, and styrenic derived units.

[0020] As used herein, the term “styrenic” refers to any styrene orsubstituted styrene monomer unit. By substituted, it is meantsubstitution of at least one hydrogen group by at least one substituentselected from, for example, halogen (chlorine, bromine, fluorine, oriodine), amino, nitro, sulfoxy (sulfonate or alkyl sulfonate), thiol,alkylthiol, and hydroxy; alkyl, straight or branched chain having 1 to20 carbon atoms; alkoxy, straight or branched chain alkoxy having 1 to20 carbon atoms, and includes, for example, methoxy, ethoxy, propoxy,isopropoxy, butoxy, isobutoxy, secondary butoxy, tertiary butoxy,pentyloxy, isopentyloxy, hexyloxy, heptryloxy, octyloxy, nonyloxy, anddecyloxy; haloalkyl, which means straight or branched chain alkyl having1 to 20 carbon atoms which is substituted by at least one halogen, andincludes, for example, chloromethyl, bromomethyl, fluoromethyl,iodomethyl, 2-chloroethyl, 2-bromoethyl, 2-fluoroethyl, 3-chloropropyl,3-bromopropyl, 3-fluoropropyl, 4-chlorobutyl, 4-fluorobutyl,dichloromethyl, dibromomethyl, difluoromethyl, diiodomethyl,2,2-dichloroethyl, 2,2-dibromomethyl, 2,2-difluoroethyl,3,3-dichloropropyl, 3,3-difluoropropyl, 4,4-dichlorobutyl,4,4-difluorobutyl, trichloromethyl, 4,4-difluorobutyl, trichloromethyl,trifluoromethyl, 2,2,2-trifluoroethyl, 2,3,3-trifluoropropyl,1,1,2,2-tetrafluoroethyl, and 2,2,3,3-tetrafluoropropyl.

[0021] As used herein, the term “substituted aryl” means phenyl,naphthyl and other aromatic groups, substituted by at least onesubstituent selected from, for example, halogen (chlorine, bromine,fluorine, or iodine), amino, nitro, sulfoxy (sulfonate or alkylsulfonate), thiol, alkylthiol, and hydroxy; alkyl, straight or branchedchain having 1 to 20 carbon atoms; alkoxy, straight or branched chainalkoxy having 1 to 20 carbon atoms, and includes, for example, methoxy,ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, secondary butoxy,tertiary butoxy, pentyloxy, isopentyloxy, hexyloxy, heptryloxy,octyloxy, nonyloxy, and decyloxy; haloalkyl, which means straight orbranched chain alkyl having 1 to 20 carbon atoms which is substituted byat least one halogen, and includes, for example, chloromethyl,bromomethyl, fluoromethyl, iodomethyl, 2-chloroethyl, 2-bromoethyl,2-fluoroethyl, 3-chloropropyl, 3-bromopropyl, 3-fluoropropyl,4-chlorobutyl, 4-fluorobutyl, dichloromethyl, dibromomethyl,difluoromethyl, diiodomethyl, 2,2-dichloroethyl, 2,2-dibromomethyl,2,2-difluoroethyl, 3,3-dichloropropyl, 3,3-difluoropropyl,4,4-dichlorobutyl, 4,4-difluorobutyl, trichloromethyl,4,4-difluorobutyl, trichloromethyl, trifluoromethyl,2,2,2-trifluoroethyl, 2,3,3-trifluoropropyl, 1,1,2,2-tetrafluoroethyl,and 2,2,3,3-tetrafluoropropyl. An “aryl” group is any aromatic ringstructure such as a phenyl or naphthyl group.

[0022] Butyl-type rubber is an isobutylene-based polymer produced by thepolymerization reaction between isoolefin and a conjugated diene—ormultiolefinic—comonomers, thus containing isoolefin-derived units andmultiolefin-derived units. The terpolymers of the present invention areprepared in a manner similar to that for traditional butyl rubbersexcept that an additional comonomer (e.g., a styrenic monomer) is alsoincorporated into the polymer chains. The olefin polymerization feedsemployed in connection with the catalyst and initiator system (describedin more detail below) are those olefinic compounds, the polymerizationof which are known to be cationically initiated. Preferably, the olefinpolymerization feeds employed in the present invention are thoseolefinic compounds conventionally used in the preparation of butyl-typerubber polymers. The terpolymers are prepared by reacting a comonomermixture, the mixture having at least (1) a C₄ to C₈ isoolefin monomercomponent such as isobutylene, (2) a styrenic monomer, and (3) amultiolefin monomer component.

[0023] The terpolymer of the present invention can be defined by rangesof each monomer derived unit. The isoolefin is in a range from at least70 wt % by weight of the total terpolymer in one embodiment, and atleast 80 wt % in another embodiment, and at least 90 wt % in yet anotherembodiment, and from 70 wt % to 99.5 wt % in yet another embodiment, and85 to 99.5 wt % in another embodiment. The styrenic monomer is presentfrom 0.5 wt % to 30 wt % by weight of the total terpolymer in oneembodiment, and from 1 wt % to 25 wt % in another embodiment, and from 2wt % to 20 wt % in yet another embodiment, and from 5 wt % to 20 wt % inyet another embodiment. The multiolefin component in one embodiment ispresent in the terpolymer from 30 wt % to 0.2 wt % in one embodiment,and from 15 wt % to 0.5 wt % in another embodiment. In yet anotherembodiment, from 8 wt % to 0.5 wt % of the terpolymer is multiolefin.Desirable embodiments of terpolymer may include any combination of anyupper wt % limit combined with any lower wt % limit by weight of theterpolymer.

[0024] The isoolefin may be a C₄ to C₈ compound, in one embodimentselected from isobutylene, isobutene, 2-methyl-1-butene,3-methyl-1-butene, 2-methyl-2-butene, and 4-methyl-1-pentene. Thestyrenic monomer may be any substituted styrene monomer unit, anddesirably is selected from styrene, α-methylstyrene or an alkylstyrene(ortho, meta, or para), the alkyl selected from any C₁ to C₅ alkyl orbranched chain alkyl. In a desirable embodiment, the styrenic monomer isp-methylstyrene. The multiolefin may be a C₄ to C₁₄ diene, conjugated ornot, in one embodiment selected from isoprene, butadiene,2,3-dimethyl-1,3-butadiene, myrcene, 6,6-dimethyl-fulvene, hexadiene,cyclopentadiene, methylcyclopentadiene, and piperylene.

[0025] Isomonoolefin, styrene-based monomers, and multiolefin monomers,particularly isobutylene, p-methylstyrene and isoprene, can becopolymerized under cationic conditions. See, for example, WO00/27807and 01/04731; U.S. Pat. No. 3,560,458, and U.S. Pat. No. 5,162,445. Thecopolymerization is carried out by means of at least one Lewis Acidcatalyst. Desirable catalysts are Lewis Acids based on metals from Group4, 13 and 15 of the Periodic Table of the Elements, including boron,aluminum, gallium, indium, titanium, zirconium, tin, vanadium, arsenic,antimony, and bismuth. In one embodiment, the metals are aluminum, boronand titanium, with aluminum being desirable.

[0026] The Group 13 Lewis Acids have the general formula R_(n)MX_(3−n),wherein “M” is a Group 13 metal, R is a monovalent hydrocarbon radicalselected from C₁ to C₁₂ alkyl, aryl, arylalkyl, alkylaryl and cycloalkylradicals; and n is an integer from 0 to 3; and X is a halogenindependently selected from fluorine, chlorine, bromine, and iodine,preferably chlorine. The term “arylalkyl” refers to a radical containingboth aliphatic and aromatic structures, the radical being at an alkylposition. The term “alkylaryl” refers to a radical containing bothaliphatic and aromatic structures, the radical being at an arylposition. Nonlimiting examples of these Lewis acids include aluminumchloride, aluminum bromide, boron trifluoride, boron trichloride, ethylaluminum dichloride (EtAlCl₂ or EADC), diethyl aluminum chloride(Et₂AlCl or DEAC), ethyl aluminum sesquichloride (Et_(1.5)AlCl_(1.5) orEASC), trimethyl aluminum, and triethyl aluminum.

[0027] The Group 4 Lewis Acids have the general formula MX₄, wherein Mis a Group 4 metal and X is a ligand, preferably a halogen. Nonlimitingexamples include titanium tetrachloride, zirconium tetrachloride, or tintetrachloride.

[0028] The Group 15 Lewis Acids have the general formula MX_(y), whereinM is a Group 15 metal, X is a ligand, preferably a halogen, and y is aninteger from 3 to 5. Nonlimiting examples include vanadium tetrachlorideand antimony pentafluoride. In one embodiment, Lewis acids may be any ofthose useful in cationic polymerization of isobutylene copolymersincluding: AlCl₃, EADC, EASC, DEAC, BF₃, TiCl₄, etc. with EASC and EADCbeing desirable in one embodiment.

[0029] Catalyst efficiency (based on Lewis Acid) in a large-scalecontinuous slurry reactor is preferably maintained between 10000 lb. ofpolymer/lb. of catalyst and 300 lb. of polymer/lb. of catalyst anddesirably in the range of 4000 lb. of polymer/lb. of catalyst to 1000lb. of polymer/lb. of catalyst by controlling the molar ratio of LewisAcid to initiator.

[0030] According to one embodiment of the invention, the Lewis Acidcatalyst is used in combination with an initiator. The initiator may bedescribed by the formula (A):

[0031] wherein X is a halogen, desirably chlorine or bromine; R₁ isselected from hydrogen, C₁ to C8 alkyls, and C₂ to C₈ alkenyls, aryl,and substituted aryl; R₃ is selected from C₁ to C₈ alkyls, C₂ to C₈alkenyls, aryls, and substituted aryls; and R₂ is selected from C₄ toC₂₀₀ alkyls, C₂ to C₈ alkenyls, aryls, and substituted aryls, C₃ to C₁₀cycloalkyls, and groups represented by the following formula (B):

[0032] wherein X is a halogen, desirably chlorine or bromine; R₅ isselected from C₁ to C₈ alkyls, and C₂ to C₈ alkenyls; R₆ is selectedfrom C₁ to C₈ alkyls, C₂ to C₈ alkenyls aryls, and substituted aryls;and R₄ is selected from phenylene, biphenyl, α,ω-diphenylalkane and—(CH₂)_(n)—, wherein n is an integer from 1 to 10; and wherein R₁, R₂,and R₃ can also form adamantyl or bornyl ring systems, the X group beingin a tertiary carbon position in one embodiment.

[0033] As used herein, the term “alkenyl” refers to singly ormultiply-unsaturated alkyl groups such as, for example, C₃H₅ group, C₄H₅group, etc.

[0034] Substitution of the above structural formula radical (B) for R₂in formula (A) results in the following formula (C):

[0035] wherein X, R₁, R₃, R₄, R₅ and R₆ are as defined above. Thecompounds represented by structural formula (C) contain two dissociablehalides.

[0036] Multifunctional initiators are employed where the production ofbranched copolymers is desired, while mono- and di-functional initiatorsare preferred for the production of substantially linear copolymers.

[0037] In one desirable embodiment, the initiator is an oligomer ofisobutylene as represented in structure (D):

[0038] wherein X is a halogen, and the value of m is from 1 to 60, andmixtures thereof. In another embodiment, m is from 2 to 40. Thisstructure is also described as a tertiary alkyl chloride-terminatedpolyisobutylene having a Mn up to 2500 in one embodiment, and up to 1200in another embodiment.

[0039] Non-limiting examples of suitable initiators are cumyl esters ofhydrocarbon acids, and alkyl cumyl ethers, other cumyl compounds and orhalogenated organic compounds, especially secondary or tertiaryhalogenated compounds such as, for example, t-butyl chloride,2-acetyl-2-phenylpropane (cumyl acetate), 2-methoxy-2-phenyl propane(cumylmethyl-ether), 1,4-di(2-methoxy-2-propyl)benzene (di(cumylmethylether)); the cumyl halides, particularly the chlorides, such as, forexample 2-chloro-2-phenylpropane, cumyl chloride(1-chloro-1-methylethyl)benzene), 1,4-di(2-chloro-2-propyl)benzene(di(cumylchloride)), and 1,3,5-tri(2-chloro-2-propyl)benzene(tri(cumylchloride)); the aliphatic halides, particularly the chlorides,such as, for example, 2-chloro-2,4,4-trimethylpentane (“TMPCl”),2-bromo-2,4,4-trimethylpentane (“TMPBr”), and2,6-dichloro-2,4,4,6-tetramethylheptane; cumyl and aliphatic hydroxylssuch as 1,4-di((2-hydroxyl-2-propyl)-benzene),2,6-dihydroxyl-2,4,4,6-tetramethyl-heptane, 1-chloroadamantane and1-chlorobornane, 5-tert-butyl-1,3-di(1-chloro-1-methyl ethyl) benzeneand similar compounds. Other suitable initiators are disclosed in U.S.Pat. Nos. 4,946,899, 3,560,458. These initiators are generally C₅ orgreater tertiary or allylic alkyl or benzylic halides and may includepolyfunctional initiators. Desirable examples of these initiatorsinclude: TMPCl, TMPBr, 2,6-dichloro-2,4,4,6-tetramethylheptane, cumylchloride as well as ‘di-’ and ‘tri-’ cumyl chloride or bromide.

[0040] The selected diluent or diluent mixture should provide a diluentmedium having some degree of polarity. To fulfil this requirement amixture of nonpolar and polar diluent can be used but one or a mixtureof polar diluents is preferred. Suitable nonpolar diluent componentsincludes hydrocarbons and preferably aromatic or cyclic hydrocarbons ormixtures thereof. Such compounds include, for instance,methylcyclohexane, cyclohexane, toluene, carbon disulfide and others.Appropriate polar diluents include halogenated hydrocarbons, normal,branched chain or cyclic hydrocarbons. Specific compounds include thepreferred liquid diluents such as ethyl chloride, methylene chloride,methylchloride (chloromethane), CHCl₃, CCl₄, n-butyl chloride,chlorobenzene, and other chlorinated hydrocarbons. To achieve suitablepolarity and solubility, it has been found that if the diluent, ordiluent mixture, is a mixture of polar and nonpolar diluents, themixture is preferably at least 70% polar component, on a volume basis.

[0041] The relative polarity of the diluent can be described in terms ofthe dielectric constant of the diluent. In one embodiment, the diluenthas a dielectric constant (as measured at from 20 to 25° C.) of greaterthan 5, and greater than 6 in another embodiment. In yet anotherembodiment, the dielectric constant of the diluent is greater than 7,and greater than 8 in yet another embodiment. In a desirable embodiment,the dielectric constant is greater than 9. Examples of dielectricconstants (20-25° C.) for single diluents are: chloromethane (10),dichloromethane (8.9), carbon disulfide (2.6), toluene (2.4), andcyclohexane (2.0) as from CRC HANDBOOK OF CHEMISTRY AND PHYSICS 6-151 to6-173 (D.R. Line, ed., 82 ed. CRC Press 2001).

[0042] As is typically the case, product molecular weights aredetermined by temperature, monomer and initiator concentration, thenature of the reactants, and similar factors. Consequently, differentreaction conditions will produce products of different molecular weightsand/or different monomer composition in the terpolymers. Synthesis ofthe desired reaction product will be achieved, therefore, throughmonitoring the course of the reaction by the examination of samplestaken periodically during the reaction, a technique widely employed inthe art and shown in the examples or by sampling the effluent of areactor.

[0043] The present invention is not herein limited by the method ofmaking the terpolymer. The terpolymer can be produced using batchpolymerization or continuous slurry polymerization, for example, and onany volume scale. The reactors that may be utilized in the practice ofthe present invention include any conventional reactors and equivalentsthereof. Preferred reactors include those capable of performing acontinuous slurry process, such as disclosed in U.S. Pat. No. 5,417,930.The reactor pump impeller can be of the up-pumping variety or thedown-pumping variety. The reactor will contain sufficient amounts of thecatalyst system of the present invention effective to catalyze thepolymerization of the monomer containing feed-stream such that asufficient amount of polymer having desired characteristics is produced.The feed-stream in one embodiment contains a total monomer concentrationgreater than 30 wt % (based on the total weight of the monomers,diluent, and catalyst system), greater than 35 wt % in anotherembodiment. In yet another embodiment, the feed-stream will contain from35 wt % to 50 wt % monomer concentration based on the total weight ofmonomer, diluent, and catalyst system. The bulk-phase, or phase in whichthe monomers and catalyst contact one another in order to react and forma polymer, may also have the same monomer concentrations.

[0044] The feed-stream or bulk-phase is substantially free from silicacation producing species in one embodiment of the invention. Bysubstantially free of silica cation producing species, it is meant thatthere is no more than 0.0005 wt % based on the total weight of themonomers of silica species in the feed stream or bulk-phase. Typicalexamples of silica cation producing species are halo-alkyl silicacompounds having the formula R₁R₂R₃SiX or R₁R₂SiX₂, etc., wherein each“R” is an alkyl and “X” is a halogen.

[0045] The reaction conditions are typically such that desirabletemperature, pressure and residence time are effective to maintain thereaction medium in the liquid state and to produce the desired polymershaving the desired characteristics. The monomer feed-stream is typicallysubstantially free of any impurity which is adversely reactive with thecatalyst under the polymerization conditions. For example, the monomerfeed preferably should be substantially free of bases (such as K₂O,NaOH, CaCO₃ and other hydroxides, oxides and carbonates),sulfur-containing compounds (such as H₂S, COS, and organo-mercaptans,e.g., methyl mercaptan, ethyl mercaptan), N-containing compounds, oxygencontaining bases such as alcohols and the like. By “substantially free”,it is meant that the above mentioned species are present, if at all, toan extent no greater than 0.0005 wt %.

[0046] In one embodiment, the ratio of monomers contacted together inthe presence of the catalyst system ranges from 98 wt % isoolefin, 1.5wt % styrenic monomer, and 0.5 wt % multiolefin (“98/1.5/0.5”), to a50/25/25 ratio by weight of the total amount of monomers. For example,the isoolefin monomer may be present from 50 wt % to 98 wt % by totalweight of the monomers in one embodiment, and from 70 wt % to 90 wt % inanother embodiment. The styrenic monomers may be present from 1.5 wt %to 25 wt % by total weight of the monomers in one embodiment, and from 5wt % to 15 wt % in another embodiment. The multiolefin may be presentfrom 0.5 wt % to 25 wt % by total weight of the monomers in oneembodiment, and from 2 wt % to 10 wt % in another embodiment, and from 3wt % to 5 wt % in yet another embodiment.

[0047] The polymerization reaction temperature is conveniently selectedbased on the target polymer molecular weight and the monomer to bepolymerized as well as standard process variable and economicconsiderations, for example, rate, temperature control, etc. Thetemperature for the polymerization is between −10° C. and the freezingpoint of the polymerization system in one embodiment, and from −25° C.to −120° C. in another embodiment. In yet another embodiment, thepolymerization temperature is from −40° C. to −100° C., and from −70° C.to −100° C. in yet another embodiment. In yet another desirableembodiment, the temperature range is from −80° C. to −99° C. Thetemperature is chosen such that the desired polymer molecular weight isachieved, the range of which may comprise any combination of any upperlimit and any lower limit disclosed herein.

[0048] The catalyst (Lewis Acid) to monomer ratio utilized are thoseconventional in this art for carbocationic polymerization processes.Particular monomer to catalyst ratios are desirable in continuous slurryor solution processes, wherein most any ratio is suitable for small,laboratory scale polymer synthesis. In one embodiment of the invention,the catalyst (Lewis acid) to monomer mole ratios will be from 0.10 to20, and in the range of 0.5 to 10 in another embodiment. In yet anotherdesirable embodiment, the ratio of Lewis Acid to initiator is from 0.75to 2.5, or from 1.25 to 1.5 in yet another desirable embodiment. Theoverall concentration of the initiator is from 50 to 300 ppm within thereactor in one embodiment, and from 100 to 250 ppm in anotherembodiment. The concentration of the initiator in the catalyst feedstream is from 500 to 3000 ppm in one embodiment, and from 1000 to 2500ppm in another embodiment. Another way to describe the amount ofinitiator in the reactor is by its amount relative to the polymer. Inone embodiment, there is from 0.25 to 5.0 moles polymer/mole initiator,and from 0.5 to 3.0 mole polymer/mole initiator in another embodiment.

[0049] It is known that chlorine or bromine can react with unsaturationof the multiolefin derived units (e.g., isoprene residue units) rapidlyto form halogenated polymer. Methods of halogenating polymers such asbutyl polymers are disclosed in U.S. Pat. No. 2,964,489; U.S. Pat. No.2,631,984; U.S. Pat. No. 3,099,644, U.S. Pat. No. 4,254,240; U.S. Pat.No. 4,554,326; U.S. Pat. No. 4,681,921; U.S. Pat. No. 4,650,831; U.S.Pat. No. 4,384,072; U.S. Pat. No. 4,513,116; and U.S. Pat. No.5,681,901. Typical halogenation processes for making halobutyl rubbersinvolves injection of a desirable amount of chlorine or bromine into thecement (solution) of butyl rubber with the reactants being mixedvigorously in the halogenation reactor with a rather short residenttime, typically less than 1 minute, following by neutralization of theHCl or HBr and any unreacted halogen. It is also well known in the artthat the specific structure of the halogenated butyl rubber iscomplicated and is believed to depend on the halogenation condition.Most commercial bromobutyl rubbers are made under the condition that theformation of “structure III” type brominated moiety is minimized, as isthe brominated terpolymer of the present invention. See, for example,Anthony Jay Dias in 5 POLYMERIC MATERIALS ENCYCLOPEDIA 3485-3492 (JosephC. Salamone, ed., CRC Press 1996). That typically means the absence offree radical sources such as light or high temperature. Alternativelythe halogenation can be carried out in polymer melt in an extruder orother rubber mixing devices in the absence of solvent.

[0050] The final level of halogen on the halogenated terpolymer,including halogen located on the polymer backbone and the styrenicmoieties incorporated therein, depends on the application and desirablecuring performance. The halogen content of a typical halogenatedterpolymer of the present invention ranges from 0.05 wt % to 5 wt % byweight of the terpolymer in one embodiment, and from 0.2 wt % to 3 wt %in another embodiment, and from 0.8 wt % to 2.5 wt % in yet anotherembodiment. In yet another embodiment, the amount of halogen present onthe terpolymer is less than 10 wt %, and less than 8 wt % in anotherembodiment, and less than 6 wt % in yet another embodiment. Statedanother way, the amount of halogen incorporated into the terpolymer isfrom less than 5 mole % in one embodiment, and from 0.1 to 2.5 mole %relative to the total moles of monomer derived units in the terpolymerin another embodiment, and from 0.2 to 2 mole % in another embodiment,and from 0.4 to 1.5 mole % in yet another embodiment. A desirable levelof halogenation may include any combination of any upper wt % or mole %limit with any lower wt % or mole % limit.

[0051] In another embodiment, the halogen content on the backbone(isoprene derived units) of a typical halogenated terpolymer of thepresent invention ranges from 0.05 wt % to 5 wt % by weight of theterpolymer in one embodiment, and from 0.2 wt % to 3 wt % in anotherembodiment, and from 0.8 wt % to 2.5 wt % in yet another embodiment. Inyet another embodiment, the amount of halogen present on the terpolymeris less than 10 wt %, and less than 8 wt % in another embodiment, andless than 6 wt % in yet another embodiment. Stated another way, theamount of halogen incorporated into the terpolymer is from less than 5mole % in one embodiment, and from 0.1 to 2.5 mole % relative to thetotal moles of monomer derived units in the terpolymer in anotherembodiment, and from 0.2 to 2 mole % in another embodiment, and from 0.4to 1.5 mole % in yet another embodiment. A desirable level ofhalogenation may include any combination of any upper wt % or mole %limit with any lower wt % or mole % limit.

[0052] In yet another embodiment, the halogen content on the styrenicmoieties, for example, p-methylstyrene (thus formingp-halomethylstyrene), was from 0.05 wt % to 5 wt %, and from 0.2 to 3 wt% in yet another embodiment, and from 0.2 wt % to 2 wt % in yet anotherembodiment, and from 0.2 wt % to 1 wt % in yet another embodiment, andfrom 0.5 wt % to 2 wt % in yet another embodiment.

[0053] The molecular weight, number average molecular weight, etc. ofthe terpolymer depends upon the reaction conditions employed, such as,for example, the amount of multiolefin present in the monomer mixtureinitially, the ratios of Lewis Acid to initiator, reactor temperature,and other factors. The terpolymer of the present invention has a numberaverage molecular weight (Mn) of up to 1,000,000 in one embodiment, andup to 800,000 in another embodiment. In yet another embodiment, theterpolymer has an Mn of up to 400,000, and up to 300,000 in yet anotherembodiment, and up to 180,000 in yet another embodiment. The Mn value ofthe terpolymer is at least 80,000 in another embodiment, and at least100,000 in yet another embodiment, and at least 150,000 in yet anotherembodiment, and at least 300,000 in yet another embodiment. A desirablerange in the Mn value of the terpolymer can be any combination of anyupper limit and any lower limit.

[0054] The terpolymer has a weight average molecular weight (Mw) of upto 2,0000,000 in one embodiment, and up to 1,000,000 in anotherembodiment, and up to 800,000 in yet another embodiment, and up to500,000 in yet another embodiment. The Mw value for the terpolymer is atleast 80,000 in yet another embodiment, and at least 100,000 in anotherembodiment, and at least 150,000 in yet another embodiment, and at least200,000 in yet another embodiment. The desirable range in the Mw valueof the terpolymer can be any combination of any upper limit and anylower limit.

[0055] The peak molecular weight value (Mp) of the terpolymer is atleast 2,000,000 in one embodiment, 100,000 another one embodiment, andat least 150,000 in another embodiment, and at least 300,000 in yetanother embodiment. The Mp value of the terpolymer is up to 600,000 inanother embodiment, and up to 400,000 in yet another embodiment. Thedesirable range in the Mp value of the terpolymer can be any combinationof any upper limit and any lower limit.

[0056] The terpolymer has a molecular weight distribution (Mw/Mn, orMWD) of less than 7.0 in one embodiment, and less than 4.0 in anotherembodiment, and from 1.5 to 3.8 in yet another embodiment. In yetanother embodiment, the MWD value is from 2.0 to 3.5. The value MWD canbe any combination of any upper limit value and any lower limit value.

[0057] Finally, the terpolymer of the invention has a Mooney viscosity(1+8, 125° C.) of from 20 to 60 MU in one embodiment, and from 25 to 70MU in another embodiment, and from 30 to 50 in yet another embodiment,and from 50 to 70 MU in yet another embodiment.

[0058] The terpolymer and/or halogenated terpolymer may be part of acomposition including other components such as one or more secondaryrubber components, a cure system, especially a sulfur cure system, atleast one filler such as carbon black or silica, and other minorcomponents common in the rubber compounding arts. The terpolymer orhalogenated terpolymer may be present from 5 phr to 100 phr in thecomposition one embodiment, from 20 phr to 100 phr in the composition inanother embodiment, and from 30 phr to 90 phr in yet another embodiment,and from 40 phr to 80 phr in yet another embodiment, and from 20 phr to50 phr in yet another embodiment, and from 15 phr to 55 phr in yetanother embodiment, and up to 100 phr in another embodiment.

Secondary Rubber Component

[0059] A secondary rubber component may be present in compositions ofthe present invention. These rubbers include, but are not limited to,natural rubbers, polyisoprene rubber, poly(styrene-co-butadiene) rubber(SBR), polybutadiene rubber (BR), poly(isoprene-co-butadiene) rubber(IBR), styrene-isoprene-butadiene rubber (SIBR), ethylene-propylenerubber (EPM), ethylene-propylene-diene rubber (EPDM), polysulfide,nitrile rubber, propylene oxide polymers, star-branched butyl rubber andhalogenated star-branched butyl rubber, brominated butyl rubber,chlorinated butyl rubber, star-branched polyisobutylene rubber,star-branched brominated butyl (polyisobutylene/isoprene copolymer)rubber; poly(isobutylene-co-p-methylstyrene) and halogenatedpoly(isobutylene-co-p-methylstyrene), such as, for example, terpolymersof isobutylene derived units, p-methylstyrene derived units, andp-bromomethylstyrene derived units, and mixtures thereof.

[0060] A desirable embodiment of the secondary rubber component presentis natural rubber. Natural rubbers are described in detail bySubramaniam in RUBBER TECHNOLOGY 179-208 (Maurice Morton, Chapman & Hall1995). Desirable embodiments of the natural rubbers of the presentinvention are selected from Malaysian rubber such as SMR CV, SMR 5, SMR10, SMR 20, and SMR 50 and mixtures thereof, wherein the natural rubbershave a Mooney viscosity at 100° C. (ML 1+4) of from 30 to 120, morepreferably from 40 to 65. The Mooney viscosity test referred to hereinis in accordance with ASTM D-1646.

[0061] Polybutadiene (BR) rubber is another desirable secondary rubberuseful in the composition of the invention. The Mooney viscosity of thepolybutadiene rubber as measured at 100° C. (ML 1+4) may range from 35to 70, from 40 to about 65 in another embodiment, and from 45 to 60 inyet another embodiment. Some commercial examples of these syntheticrubbers useful in the present invention are NATSYN™ (Goodyear ChemicalCompany), and BUDENE™ 1207 or BR 1207 (Goodyear Chemical Company). Adesirable rubber is high cis-polybutadiene (cis-BR). By“cis-polybutadiene” or “high cis-polybutadiene”, it is meant that1,4-cis polybutadiene is used, wherein the amount of cis component is atleast 95%. An example of high cis-polybutadiene commercial products usedin the composition BUDENE™ 1207.

[0062] Rubbers of ethylene and propylene derived units such as EPM andEPDM are also suitable as secondary rubbers. Examples of suitablecomonomers in making EPDM are ethylidene norbornene, 1,4-hexadiene,dicyclopentadiene, as well as others. These rubbers are described inRUBBER TECHNOLOGY 260-283 (1995). A suitable ethylene-propylene rubberis commercially available as VISTALON™ (ExxonMobil Chemical Company,Houston Tex.).

[0063] In another embodiment, the secondary rubber is a halogenatedrubber as part of the terpolymer composition. The halogenated butylrubber is brominated butyl rubber, and in another embodiment ischlorinated butyl rubber. General properties and processing ofhalogenated butyl rubbers is described in THE VANDERBILT RUBBER HANDBOOK105-122 (Robert F. Ohm ed., R. T. Vanderbilt Co., Inc. 1990), and inRUBBER TECHNOLOGY 311-321 (1995). Butyl rubbers, halogenated butylrubbers, and star-branched butyl rubbers are described by Edward Kresgeand H. C. Wang in 8 KIRK-OTHMER ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY934-955 (John Wiley & Sons, Inc. 4th ed. 1993).

[0064] The secondary rubber component of the present invention includes,but is not limited to at least one or more of brominated butyl rubber,chlorinated butyl rubber, star-branched polyisobutylene rubber,star-branched brominated butyl (polyisobutylene/isoprene copolymer)rubber; halogenated poly(isobutylene-co-p-methylstyrene), such as, forexample, terpolymers of isobutylene derived units, p-methylstyrenederived units, and p-bromomethylstyrene derived units (BrIBMS), and thelike halomethylated aromatic interpolymers as in U.S. Pat. No.5,162,445; U.S. Pat. No. 4,074,035; and U.S. Pat. No. 4,395,506;halogenated isoprene and halogenated isobutylene copolymers,polychloroprene, and the like, and mixtures of any of the above. Someembodiments of the halogenated rubber component are also described inU.S. Pat. No. 4,703,091 and U.S. Pat. No. 4,632,963.

[0065] In one embodiment of the invention, a so called semi-crystallinecopolymer (“SCC”) is present as the secondary “rubber” component.Semi-crystalline copolymers are described in WO00/69966. Generally, theSCC is a copolymer of ethylene or propylene derived units and α-olefinderived units, the α-olefin having from 4 to 16 carbon atoms in oneembodiment, and in another embodiment the SCC is a copolymer of ethylenederived units and α-olefin derived units, the α-olefin having from 4 to10 carbon atoms, wherein the SCC has some degree of crystallinity. In afurther embodiment, the SCC is a copolymer of 1-butene derived units andanother α-olefin derived unit, the other α-olefin having from 5 to 16carbon atoms, wherein the SCC also has some degree of crystallinity. TheSCC can also be a copolymer of ethylene and styrene.

[0066] The secondary rubber component of the elastomer composition maybe present in a range from up to 90 phr in one embodiment, from up to 50phr in another embodiment, from up to 40 phr in another embodiment, andfrom up to 30 phr in yet another embodiment. In yet another embodiment,the secondary rubber is present from at least 2 phr, and from at least 5phr in another embodiment, and from at least 5 phr in yet anotherembodiment, and from at least 10 phr in yet another embodiment. Adesirable embodiment may include any combination of any upper phr limitand any lower phr limit. For example, the secondary rubber, eitherindividually or as a blend of rubbers such as, for example NR and BR,may be present from 5 phr to 90 phr in one embodiment, and from 10 to 80phr in another embodiment, and from 30 to 70 phr in yet anotherembodiment, and from 40 to 60 phr in yet another embodiment, and from 5to 50 phr in yet another embodiment, and from 5 to 40 phr in yet anotherembodiment, and from 20 to 60 phr in yet another embodiment, and from 20to 50 phr in yet another embodiment, the chosen embodiment dependingupon the desired end use application of the composition.

Filler

[0067] Elastomeric compositions suitable for an air barrier of theinvention may include one or more filler components such as calciumcarbonate, clay, mica, silica and silicates, talc, titanium dioxide,starch and other organic fillers such as wood flower, and carbon black.In one embodiment, the filler is carbon black or modified carbon black.In one embodiment, the filler is reinforcing grade carbon black presentat a level of from 10 to 150 phr, preferably 10 to 100 phr, of thecomposition, preferably from 30 to 120 phr, more preferably 40 to 80phr. Useful grades of carbon black are described in RUBBER TECHNOLOGY59-85 (1995) and range from N110 to N990. More desirably, embodiments ofthe carbon black useful in, for example, tire treads are N229, N351,N339, N220, N234 and N110 provided in ASTM (D3037, D1510, and D3765).Embodiments of the carbon black useful in, for example, sidewalls intires, are N330, N351, N550, N650, N660, and N762. Embodiments of thecarbon black useful in, for example, innerliners or innertubes are N550,N650, N660, N762, N990, and Regal 85 (Cabot Corporation, Alpharetta,Ga.) and the like.

[0068] Modified carbon blacks may also be suitable as a filler. Such“modified carbon black” is disclosed in, for example, U.S. Pat. Nos.3,620,792; 5,900,029; and 6,158,488. For example, the modified carbonblack may comprise carbon black that has been subjected to treatmentwith a gas such as a nitrogen oxide, ozone, or other gas which mayimpart improved properties to the surface of the carbon black. Themodified carbon black may also comprise, for example, a carbon blackthat has been contacted with a silanol-containing compound and/or ahydrocarbon radical such as an alkyl, aryl, alkylaryl and arylalkyl. Themodified carbon black contacted with a silanol-containing compound canbe prepared, for example, by contacting an organosilane such as an alkylalkoxy silane with carbon black at an elevated temperature.Representative organosilanes include tetraakoxysilicates such astetraethyoxysilicate. Alternatively, the modified carbon black can beprepared by co-fuming an organosilane and an oil in the presence of thecarbon black at an elevated temperature. In yet another examplepreparing a modified carbon black, a diazonium salt can be contactedwith the carbon black either with or without an electron source or withor without a protic solvent. Diazonium salts are known in the art andmay be generated by contacting a primary amine, a nitrile and an acid(proton donor). The nitrile may be any metal nitrile, desirably alithium nitrile, sodium nitrile, potassium nitrile, zinc nitrile, orsome combination thereof, or any organic nitrile such as isoamylnitrileor ethylnitrile, or some combination of these.

[0069] Exfoliated clays may also be present in the composition. Theseclays, also referred to as “nanoclays”, are well known, and theiridentity, methods of preparation and blending with polymers is disclosedin, for example, JP2000109635; JP2000109605; JP11310643; DE19726278;WO98/53000; U.S. Pat. No. 5,091,462; U.S. Pat. No. 4,431,755; U.S. Pat.No. 4,472,538; and U.S. Pat. No. 5,910,523. Swellable layered claymaterials suitable for the purposes of this invention include natural orsynthetic phyllosilicates, particularly smectic clays such asmontmorillonite, nontronite, beidellite, volkonskoite, laponite,hectorite, saponite, sauconite, magadite, kenyaite, stevensite and thelike, as well as vermiculite, halloysite, aluminate oxides, hydrotalciteand the like. These layered clays generally comprise particlescontaining a plurality of silicate platelets having a thickness of from4-20 Å in one embodiment, 8-12 Å in another embodiment, bound togetherand contain exchangeable cations such as Na⁺, Ca⁺², K⁺ or Mg³⁰ ² presentat the interlayer surfaces.

[0070] The layered clay may be intercalated and exfoliated by treatmentwith organic molecules (swelling agents) capable of undergoing ionexchange reactions with the cations present at the interlayer surfacesof the layered silicate. Suitable swelling agents include cationicsurfactants such as ammonium, alkylamines or alkylammonium (primary,secondary, tertiary and quaternary), phosphonium or sulfoniumderivatives of aliphatic, aromatic or arylaliphatic amines, phosphinesand sulfides. Desirable amine compounds (or the corresponding ammoniumion) are those with the structure R₁R₂R₃N, wherein R₁, R₂, and R₃ are C₁to C₂₀ alkyls or alkenes which may be the same or different. In oneembodiment, the exfoliating agent is a long chain tertiary amine,wherein at least R₁ is a C₁₄ to C₂₀ alkyl or alkene.

[0071] Another class of swelling agents include those which can becovalently bonded to the interlayer surfaces. These include polysilanesof the structure—Si(R′)₂R² where R′ is the same or different at eachoccurrence and is selected from alkyl, alkoxy or oxysilane and R² is anorganic radical compatible or soluble with the matrix polymer of thecomposite.

[0072] Other suitable swelling agents include protonated amino acids andsalts thereof containing 2-30 carbon atoms such as 12-aminododecanoicacid, epsilon-caprolactam and like materials. Suitable swelling agentsand processes for intercalating layered silicates are disclosed in U.S.Pat. No. 4,472,538; U.S. Pat. No. 4,810,734; U.S. Pat. No. 4,889,885; aswell as WO92/02582.

[0073] In one embodiment of the invention, the exfoliating additive iscombined with the halogenated terpolymer. In one embodiment, theadditive includes all primary, secondary and tertiary amines andphosphines; alkyl and aryl sulfides and thiols; and their polyfunctionalversions. Desirable additives include: long-chain tertiary amines suchas N,N-dimethyl-octadecylamine, N,N-diociadecyl-methylamine, so calleddihydrogenated tallowalkyl-methylamine and the like, andamine-terminated polytetrahydrofuran; long-chain thiol and thiosulfatecompounds like hexamethylene sodium thiosulfate. In another embodimentof the invention, improved interpolymer impermeability is achieved bythe presence of polyfunctional curatives such as hexamethylenebis(sodium thiosulfate) and hexamethylene bis(cinnamaldehyde).

[0074] In yet another embodiment of the composition, the filler may be amineral filler such as silica. A description of desirable mineralfillers is described by Walter H. Waddell and Larry R. Evans in RUBBERTECHNOLOGY, COMPOUNDING AND TESTING FOR PERFORMANCE 325-332 (John S.Dick, ed. Hanser Publishers 2001). Such mineral fillers include calciumcarbonate and other alkaline earth and alkali metal carbonates, bariumsulfate and other metal sulfates, ground crystalline silica, biogenicsilica, such as from dolomite, kaolin clay and other alumina-silicateclays, talc and other magnesium-silica compounds, alumina, metal oxidessuch as titanium oxide and other Group 3-12 metal oxides, any of whichnamed above can be precipitated by techniques known to those skilled inthe art. Particularly desirable mineral fillers include precipitatedsilicas and silicates. Other suitable non-black fillers and processingagents (e.g., coupling agents) for these fillers are disclosed in theBLUE BOOK 275-302, 405-410 (Lippincott & Peto Publications, RubberWorld2001).

[0075] When such mineral fillers are present, it is desirable to alsoinclude organosilane coupling agents. The coupling agent is typically abifunctional organosilane cross-linking agent. By an “silane couplingagent” is meant any silane coupled filler and/or cross-linking activatorand/or silane reinforcing agent known to those skilled in the artincluding, but not limited to, vinyl triethoxysilane,vinyl-tris-(beta-methoxyethoxy)silane,methacryloylpropyltrimethoxysilane, gamma-amino-propyl triethoxysilane(sold commercially as A1100 by Witco),gamma-mercaptopropyltrimethoxysilane (A189 by Witco) and the like, andmixtures thereof. In a preferred embodiment,bis-(3(triethoxysilyl)-propyl)-tetrasulfane (sold commercially as Si69by Degussa AG, Germany) is employed. Preferably, theorganosilane-coupling agent composes from 2 to 15 weight percent, basedon the weight of filler, of the elastomeric composition in oneembodiment. More preferably, it composes from 4 to 12 weight percent ofthe filler in yet another embodiment.

[0076] The filler component of the elastomer composition may be presentin a range from up to 120 phr in one embodiment, from up to 100 phr inanother embodiment, and from up to 60 phr in yet another embodiment. Inyet another embodiment, the filler is present from 5 phr to 80 phr, from50 phr to 80 phr in yet another embodiment, from 20 phr to 80 phr in yetanother embodiment, from 10 phr to 70 phr in yet another embodiment,from 50 phr to 70 phr in yet another embodiment, and from 60 phr to 90phr in yet another embodiment, wherein a desirable range can by anycombination of any upper phr limit and any lower phr limit.

Curing Agents and Accelerators

[0077] The compositions produced in accordance with the presentinvention typically contain other components and additives customarilyused in rubber mixes, such as pigments, accelerators, cross-linking andcuring materials, antioxidants, antiozonants, and fillers.

[0078] Generally, polymer compositions, for example, those used toproduce tires, are crosslinked. It is known that the physicalproperties, performance characteristics, and durability of vulcanizedrubber compounds are directly related to the number (crosslink density)and type of crosslinks formed during the vulcanization reaction. (See,e.g., W. Helt et al., The Post Vulcanization Stabilization for NR,RUBBER WORLD 18-23 (1991). Cross-linking and curing agents includesulfur, zinc oxide, and fatty acids. Peroxide cure systems may also beused.

[0079] More particularly, in a desirable embodiment of the compositionof the invention, a “sulfur cure system” is present in the composition.The sulfur cure system of the present invention includes at least oneore more sulfur compounds such as elemental sulfur, and may includesulfur-based accelerators. Generally, the terpolymer compositions mayalso include other curative components such as, for example sulfur,metal oxides (e.g., zinc oxide), organometallic compounds, radicalinitiators, etc. followed by heating. In particular, the following arecommon curatives that will function in the present invention: ZnO, CaO,MgO, Al₂O₃, CrO₃, FeO, Fe₂O₃, and NiO. These metal oxides can be used inconjunction with a corresponding metal complex, or with a correspondingagent such as a C₆ to C₃₀ fatty acid such as stearic acid, etc. (e.g.,Zn(Stearate)₂, Ca(Stearate)₂, Mg(Stearate)₂, and Al(Stearate)₃), andeither a sulfur compound or an alkylperoxide compound. (See also,Formulation Design and Curing Characteristics of NBR Mixes for Seals,RUBBER WORLD 25-30 (1993). This method may be accelerated and is oftenused for the vulcanization of elastomer compositions. The sulfur curesystem of the present invention includes at least sulfur, typicallyelemental sulfur, and may also include the metal oxides, acceleratorsand phenolic resins disclosed herein.

[0080] Accelerators include amines, guanidines, thioureas, thiazoles,thiurams, sulfenamides, sulfenimides, thiocarbamates, xanthates, and thelike. Acceleration of the cure process may be accomplished by adding tothe composition an amount of the accelerant. The mechanism foraccelerated vulcanization of natural rubber involves complexinteractions between the curative, accelerator, activators and polymers.Ideally, all of the available curative is consumed in the formation ofeffective crosslinks which join together two polymer chains and enhancethe overall strength of the polymer matrix. Numerous accelerators areknown in the art and include, but are not limited to, the following:stearic acid, diphenyl guanidine (DPG), tetramethylthiuram disulfide(TMTD), 4,4′-dithiodimorpholine (DTDM), tetrabutylthiuram disulfide(TBTD), 2,2′-benzothiazyl disulfide (MBTS),hexamethylene-1,6-bisthiosulfate disodium salt dihydrate,2-(morpholinothio) benzothiazole (MBS or MOR), compositions of 90% MORand 10% MBTS (MOR 90), N-tertiarybutyl-2-benzothiazole sulfenamide(TBBS), and N-oxydiethylene thiocarbamyl-N-oxydiethylene sulfonamide(OTOS), zinc 2-ethyl hexanoafe (ZEH), N,N′-diethyl thiourea.

[0081] The compositions of the invention may also include processingoils and resins such as paraffinic, polybutene, naphthenic or aliphaticresins and oils. Processing aids include, but are not limited to,plasticizers, tackifiers, extenders, chemical conditioners, homogenizingagents and peptizers such as mercaptans, petroleum and vulcanizedvegetable oils, waxes, resins, rosins, and the like. The aid istypically present from 1 to 70 phr in one embodiment, from 5 to 60 phrin another embodiment, and from 10 to 50 phr in yet another embodiment.Some commercial examples of processing aids are SUNDEX™ (Sun Chemicals),FLEXON™ and PARAPOL™ (ExxonMobil Chemical), and CALSOL™ (R. E. Carroll).Other suitable additives are described by Howard L. Stevens in RUBBERTECHNOLOGY 20-58 (1995), especially in Tables 2.15 and 2.18.

[0082] In one embodiment of the invention, at least one curing agent(s)is present from 0.2 to 15 phr, and from 0.5 to 10 phr in anotherembodiment, and from 2 phr to 8 phr in yet another embodiment. Curingagents include those components described above that facilitate orinfluence the cure of elastomers, such as metals, accelerators, sulfur,peroxides, and other agents common in the art.

[0083] The compositions may be vulcanized (cured) by any suitable meanssuch as by subjecting them using heat or radiation according to anyconventional vulcanization process. The amount of heat or radiation(“heat”) is that required to affect a cure in the composition, and theinvention is not herein limited to the method and amount of heatrequired to cure the composition in forming a stock material or article.Typically, the vulcanization is conducted at a temperature ranging fromabout 100° C. to about 250° C. in one embodiment, from 150° C. to 200°C. in another embodiment, for about 1 to 150 minutes.

[0084] Suitable elastomeric compositions for such articles as tireinnerliners or innertubes may be prepared by using conventional mixingtechniques including, e.g., kneading, roller milling, extruder mixing,internal mixing (such as with a Banbury™ mixer) etc. The sequence ofmixing and temperatures employed are well known to the skilled rubbercompounder, the objective being the dispersion of fillers, activatorsand curatives in the polymer matrix without excessive heat buildup. Auseful mixing procedure utilizes a Banbury™ mixer in which the polymerrubber, carbon black and plasticizer are added and the composition mixedfor the desired time or to a particular temperature to achieve adequatedispersion of the ingredients. Alternatively, the rubber and a portionof the carbon black (e.g., one-third to two thirds) is mixed for a shorttime (e.g., about 1 to 3 minutes) followed by the remainder of thecarbon black and oil. Mixing is continued for about 1 to 10 minutes athigh rotor speed during which time the mixed components reach atemperature of about 140° C. Following cooling, the components are mixedin a second step on a rubber mill or in a Banbury™ mixer during whichthe curing agent and optional accelerators, are thoroughly and uniformlydispersed at relatively low temperature, e.g., about 80° C. to about105° C., to avoid premature curing of the composition. Variations inmixing will be readily apparent to those skilled in the art and thepresent invention is not limited to any specific mixing procedure. Themixing is performed to disperse all components of the compositionthoroughly and uniformly.

[0085] An innerliner stock is then prepared by calendering or extrudingthe compounded rubber composition into a sheet having a thickness ofroughly 40 to 100 mil gauge and cutting the sheet material into stripsof appropriate width and length for innerliner applications in the tirebuilding operation. The liner can then be cured while in contact withthe tire carcass and/or sidewall in which it is placed.

[0086] An innertube stock is prepared by extruding the compounded rubbercomposition into a tubular shape having a thickness of from 50 to 150mil gauge and cutting the extruded material into a length of appropriatesize. The tubes of extruded material are then second cut and the endsspliced together to form the green tube. The tube is then cured to formthe finished innertube either by heating from 25° C. to 250° C., orexposure to radiation, or by other techniques known to those skilled inthe art.

Test Methods

[0087] Cure properties were measured using a MDR 2000 at the indicatedtemperature and 0.5 degree arc. Test specimens were cured at theindicated temperature, typically from 150° C. to 160° C., for a time (inminutes) corresponding to T90+ appropriate mold lag. When possible,standard ASTM tests were used to determine the cured compound physicalproperties. Stress/strain properties (tensile strength, elongation atbreak, modulus values, energy to break) were measured at roomtemperature using an Instron 4202 or Instron 4204. Shore A hardness wasmeasured at room temperature by using a Zwick Duromatic. Abrasion losswas determined at room temperature by weight difference by using anAPH-40 Abrasion Tester with rotating sample holder (5 N counter balance)and rotating drum. Weight losses were indexed to that of the standardDIN compound with lower losses indicative of a higher DIN abrasionresistance index. The weight losses can be measured with an error of±5%.

[0088] Temperature-dependent (−80° C. to 60° C.) dynamic properties (G*,G′, G″ and tangent delta) were obtained using a Rheometrics ARES. Arectangular torsion sample geometry was tested at 1 or 10 Hz and 2%strain. The temperature-dependent tangent delta curve (such as generatedin, e.g., FIG. 1) maximizes at a temperature affording information usedto predict tire performance. The tangent delta values are measured withan error of ±5%, while the temperature is measured with an error of ±2°C. Values of G″ or tangent delta measured in the range from −10° C. to10° C. in laboratory dynamic testing can be used as predictors of tirewet traction, while values of from −20° C. to −40° C. are used topredict winter traction. Values of tangent delta measured in the rangeof from 50° C. to 70° C. in laboratory dynamic testing can be used aspredictors of tire rolling resistance.

[0089] Gel permeation chromatography was used to determine molecularweight data for the terpolymers. The values of number average molecularweight (Mn), weight average molecular weight (Mw) and peak molecularweight (Mp) obtained have an error of ±20%. The techniques fordetermining the molecular weight and molecular weight distribution (MWD)are generally described in U.S. Pat. No. 4,540,753 to Cozewith et al.and references cited therein, and in Verstrate et al., 21 MACROMOLECULES3360 (1988). In a typical measurement, a 3-column set is operated at 30°C. The elution solvent used may be stabilized tetrahydrofuran (THF), or1,2,4-trichlorobenzene (TCB). The columns are calibrated usingpolystyrene standards of precisely known molecular weights. Acorrelation of polystyrene retention volume obtained from the standards,to the retention volume of the polymer tested yields the polymermolecular weight. ¹H- and decoupled ³C-NMR spectroscopic analyses wererun in either CDCl₃ or toluene-d₈ at ambient temperature using a fieldstrength of 250 MHz (¹³C-63 MHz) or in tetrachloroethane-d₂ at 120° C.using a field strength of 500 MHz (¹³C-125 MHz) depending upon thesample's solubility. Incorporation (mol %) of isobutylene and isopreneinto the terpolymers of all examples was determined by comparison theintegration of the methyl proton resonances with those of the methyleneproton resonances and resonances specific for the PMS.

[0090] Oxygen permeability was measured using a MOCON OxTran Model 2/61operating under the principle of dynamic measurement of oxygen transportthrough a thin film as published by R. A. Pasternak et al. in 8 JOURNALOF POLYMER SCIENCE: PART A-2 467 (1970). The units of measure arecc-mil/m ²-day-mmHg. Generally, the method is as follows: flat film orrubber samples are clamped into diffusion cells which are purged ofresidual oxygen using an oxygen free carrier gas at 60° C. The carriergas is routed to a sensor until a stable zero value is established. Pureoxygen or air is then introduced into the outside of the chamber of thediffusion cells. The oxygen diffusing through the film to the insidechamber is conveyed to a sensor which measures the oxygen diffusionrate.

[0091] Air permeability was tested by the following method. Thin,vulcanized test specimens from the sample compositions were mounted indiffusion cells and conditioned in an oil bath at 65° C. The timerequired for air to permeate through a given specimen is recorded todetermine its air permeability. Test specimens were circular plates with12.7-cm diameter and 0.38-mm thickness. The error (2σ) in measuring airpermeability is ±0.245 (×10 ⁸) units. Other test methods are describedin Table 2.

[0092] Adhesion to SBR Test. This test method, the “adhesion to SBR” or“adhesion T-peel” test is based on ASTM D413. This test is used todetermine the adhesive bond strength between two rubber compounds, thesame or different, after curing. Generally, the compounds used to makeup the rubber (elastomeric) compositions are prepared on a three-rollmill to a thickness of 2.5 mm. An adhesive backing fabric is placed onthe back of each compound. Typically, approximately 500 grams of stockblended elastomeric composition yields 16 samples which is enough for 8adhesion tests in duplicate, wherein the calender is set to 2.5 mmguides spaced 11 cm apart.

[0093] The face of the two compounds are pressed and bonded to oneanother. A small Mylar tab is placed between the two layers of rubbercompositions (SBR and test composition) on one end to prevent adhesion,and to allow approximately 2.5 inches (6.35 cm) of tab area. The samplesare then cure bonded in a curing press at the specified conditions. Dieout 1 inch (2.54 cm) ×6 inch (15.24 cm) specimen from each moldedvulcanized piece. The tab of each specimen is held by a powered driventensioning machine (Instron 4104, 4202, or 1101) and pulled at 180°until separation between the two rubber compositions occurs. Force toobtain separation and observations are then reported.

[0094] Other test methods are summarized in Table 1.

EXAMPLES

[0095] The present invention, while not meant to be limiting by, may bebetter understood by reference to the following examples and Tables. Thefollowing symbols are used throughout this description to describerubber components of the invention: IBIMS {terpolymer;poly(isobutylene-co-p-methylstyrene-co-isoprene)}; BrIBIMS {(brominatedterpolymer; brominatedpoly(isobutylene-co-p-methylstyrene-co-isoprene)}; IBMS{poly(isobutylene-co-p-methylstyrene)}; BrIBMS(poly(isobutylene-co-p-methylstyrene-co-p-bromomethylstyrene)}; SBB{brominated star branched butyl rubber (poly(isobutylene-co-isoprene))};BR {polybutadiene}; NR {natural rubber}; SBR {styrene-butadiene rubber};and BIIR {brominated poly(isobutylene-co-isoprene)}.

[0096] The synthesis of the terpolymer useful in the invention wascarried out in a set of 6 sample batch runs. Tertiary-butylchloride(t-BuCl) was the initiator used in runs A-F, data for which is shown inTable 3A.

[0097] For the runs A-F, the batch experiments were 250 mL reactions inchloromethane at an initial temperature of −93° C. The initiator used inthe examples was t-butylchloride (Aldrich Chemical Co.) and the Lewisacid catalyst used was 25 wt % solution of EADC(ethylaluminumdichloride) in heptane. The t-butylchloride initiator andEADC catalyst were pre-mixed at 3/1 molar ratio in chloromethane anddiluted to a final total concentration of about 1 wt % solution inchoromethane.

[0098] The isobutylene used in the examples was dried by passing theisobutylene vapor through drying columns, and then condensed in a cleanflask in a dry box prior to use. The p-methylstyrene and isoprenemonomers used in the examples were distilled under vacuum to removemoisture and free radical inhibitor prior to use. The monomer feed blendused in the terpolymer synthesis of runs A-F was a 10 wt % totalmonomers in chloromethane with 80/10/10 wt % ratio ofisobutylene/isoprene/p-methylstyrene.

[0099] The terpolymerization experiments were carried out in 500 mlglass reactors in a standard nitrogen atmosphere enclosure box (dry box)equipped with a cooling bath for low temperature reactions. Eachpolymerization batch used 250 ml of the monomer feed blend contained80/10/10 wt % ratio of isobutylene/isoprene/p-methylstyrene at 10 wt %total monomers in chloromethane. After the monomer solution was cooleddown to desired reaction temperature (<−90° C.), the pre-chilledinitiator/catalyst mixture solution was added slowly to the reactor toinitiate the polymerization. The rate of catalyst solution addition wascontrolled to avoid excessive temperature buildup in the reactor. Thus,catalyst was added incrementally to the bulk-phase within the reactor.The amount of total catalyst solution added was adjusted based on, amongother factors, the accumulated temperature increases that correlate withamount of monomers consumed in the reactor. When desirable monomerconversion was reached (e.g., at least 50% conversion), a small amountof methanol was added to the reactor to quench the polymerizationreactions. The terpolymer was then isolated and dried in a vacuum ovenfor analysis.

[0100] The molecular weight and molecular weight distribution (Mw/Mn) ofthe resultant terpolymers were analyzed by standard Gel PermeationChromatography (GPC) techniques known in the art (described above). TheGPC analysis results of the terpolymers are shown in Table 3. The mole %ratios of monomer derived units in the final terpolymers obtained bystandard proton NMR technique are also shown in Table 3A. The compositeamount of unsaturated groups (also corresponding to the level ofisoprene {IP}) in the terpolymer of runs A-F is 4.14 mole %. Thecomposite amount of PMS in the final terpolymer of runs A-F is 4.64 mole%.

[0101] Bromination of the A-F terpolymer composite was carried out instandard round bottomed flasks using 5 wt % terpolymer solution incyclohexane. In order to minimize free radical bromination, the reactorwas completely shielded from light and a small amount (about 200 ppmbased on polymer charge) of BHT free radical inhibitor was added in thepolymer solution. A 10 wt % bromine solution in cyclohexane was preparedand transferred into a graduated addition funnel attached to thereactor. Desired amount of the bromine solution was then added dropwiseinto the terpolymer solution with vigorous agitation. The brominationreaction was quenched with excessive caustic solution 2-5 minutes afterthe bromine addition was completed. The excess caustic in theneutralized terpolymer solution was then washed with fresh water inseparatory funnel several times. The brominated terpolymer was isolatedby solvent precipitation in methanol and then dried in vacuum oven atmoderate temperature overnight.

[0102] Bromination resulted mostly in bromination of the unsaturation inthe backbone of the terpolymer, with some bromination of the PMS. Thelevel of bromine in the composite sample on the backbone is 0.80 mole %,and 0.06 mole % on the PMS as determined by NMR (total 0.86 mole %bromine). This sample was used in example 3. Another batch of terpolymerwas subjected to bromination similarly to that above, resulting in acomposite bromine level of 1.1 mole % (±10%). This sample was used forexample 7.

[0103] In demonstrating the cure characteristics of the IBIMS, the A-Fcomposite, and other comparative compounds, examples 1-3 were mixed intwo stages using a Haake Rheomix™ 600 internal mixer. Elastomers,fillers, and processing oil were mixed in the first step. Ingredientsare listed in Table 3. The second step consisted of mixing the firststep masterbatch and adding all other chemical ingredients. Mixingcontinued for three minutes or until a temperature of 110° C. wasreached. An open two-roll mill was used to sheet out the stocks aftereach Haake mixing step.

[0104] Examples of the compositions (1-7) used to study the curecharacteristics of the terpolymer are found in Table 4, the propertiesof which are summarized in Table 5. Samples 1-7 represent the terpolymerin comparison with other known rubbers. Each sample 1-7 includes 60 phrN666 carbon black; 4 phr SP-1068 resin; 7 phr STRUKTOL 40 MS; 1 phrstearic acid; 8 phr CALSOL 810 processing oil; 0.15 phr MAGLITE-K; 1 phrKADOX 911 zinc oxide; 0.5 phr sulfur; and 1.25 phr MBTS. The cureproperties are summarized in Table 5, and the physical characteristicsare summarized in Table 6. Aged properties of samples 4-7, and adhesionto SBR tests, are summarized in Table 7. Finally, the dynamic properties(tangent delta) values of examples 4-7 are summarized in Table 8 andFIG. 1.

[0105] The results of the physical studies outlined in Tables 5-7 showthat the BrIBIMS Compound 7 has similar cure properties to the otherisobutylene-based polymers studied: bromobutyl rubber, star-branchedbromobutyl rubber and BIMS. Slightly lower mechanical properties (100%and 300% modulus, tensile and energy to break values) are obtainedprimarily thought due to the lower molecular weight of the BrIBIMSterpolymer (see Table 6) as indicated by the much lower Mooney viscosityvalue obtained for the innerliner compound. The BrIBIMS innerlinerCompound 7 has the same desirably low air permeability as the otherisobutylene elastomers. However, surprisingly in spite of this lowmolecular weight the BrIBIMS Compound 7 has higher abrasion resistancevalues than the bromobutyl rubber (5) or star-branched bromobutyl rubber(4) innerliners and is comparable to the BIMS Compound 6. In addition,the BrIBIMS Compound 7 has higher adhesion to a SBR carcass compound anda higher tear strength than does the BIMS Compound 6.

[0106] Dynamic property testing shows that the BrIBIMS terpolymerCompound 7 has higher tangent delta values at temperatures between +30°C. and −20° C. indicating potential improved dry, wet and wintertraction properties, see FIG. 1. This property is useful in rubberproducts where traction or grip is an important performance propertysuch as in tire treads, shoe outsoles, and power transmission belts.Table 8 is a summary of the results shown in FIG. 1.

[0107] The examples 3 and 7 above were performed using a BrIBIMSterpolymer having a collective (combination of several batches) numberaverage molecular weight of about 90,000. Given this relatively lowmolecular weight, it is surprising that the adhesion to SBR value inTable 7 is as high as 70 N/mm. Thus, while the tensile strength andenergy to break values of the example 7 BrIBIMS are low relative to, forexample BIIR, this would be expected for a polymer having the relativelylow number average molecular weight exhibited in the example 7 BrIBIMS.In a prospective example BrIBIMS, the number average molecular weight ofthe terpolymer is between 300,000 and 800,000, or between 300,000 and600,000 in another embodiment. This terpolymer may be achieved byadjusting the reaction conditions such as the identity and/or quantityof initiator, the reactor temperature, and other factors. This 300,000to 800,000 number average molecular weight BrIBIMS terpolymer would beexpected to exhibit a further improved adhesion to SBR value of from 80to 300 N/mm or greater. The DIN Abrasion Index of this higher MWterpolymer would be greater than 60 in one embodiment, and greater than70 in yet another embodiment, and greater than 80 in yet anotherembodiment. Finally, the Mooney viscosity (ML (1+4) at 100° C.) of the300,000 to 800,000 number average molecular weight BrIBIMS terpolymerwould be from 50 to 70 units.

[0108] Thus, in a desirable embodiment, the terpolymer of the invention,with a filler and alternatively with other additional rubbers and othercomponents, exhibits an adhesion to SBR value at 100° C. of from greaterthan 70 N/mm in one embodiment, greater than 80 N/mm in anotherembodiment, greater than 100 N/mm in yet another embodiment, and greaterthan 200 N/mm in yet another embodiment, and from 70 to 400 N/mm in oneembodiment, and from 80 to 300 N/mm in yet another embodiment.

[0109] The terpolymer of the present invention, in combination with asuitable filler, and alternatively, one or more additional secondaryrubbers, can be cured by any suitable means to form various usefularticles. In particular, the cured terpolymers of the invention aresuitable for automotive tire components such as treads, sidewalls and,particularly suitable for tire innerliners, innertubes, and otherapplications where air barrier qualities are desirable. The terpolymer,or compositions of the terpolymer, may also be suitable for sucharticles as belts and hoses, vibrational damping devices, pharmaceuticalstoppers and plungers, shoe soles and other shoe components, and otherdevices where air impermeability and flexibility are important.

[0110] The composition of the present invention may be used in producinginnerliners for motor vehicle tires such as truck tires, bus tires,passenger automobile tires, motorcycle tires, off the road tires, andthe like. The oxygen permeability (MOCON) of the cured compositions ofthe invention is less than 10×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C. in oneembodiment, less than 9.5×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C. in anotherembodiment, and less than 9.0×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C. in yetanother embodiment, and less than 8.5×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C.in yet another embodiment; and the oxygen permeability may range from0.1×10⁻⁸ to 10×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C. in one embodiment, andfrom 1×10⁻⁸ to 9×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C. in anotherembodiment, and from 1.5×10⁻⁸ to 9 ×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C. inyet another embodiment.

[0111] The cured composition of the present invention, in combinationwith a suitable filler, and alternately, an additional rubber and othercomponents, may have a DIN Abrasion Index of from greater than 45 in oneembodiment, and greater than 50 in another embodiment, and greater than52 in yet another embodiment; and a DIN Abrasion Index from 30 to 80 inyet another embodiment, and from 40 to 70 in yet another embodiment, andfrom 45 to 65 in yet another embodiment.

[0112] Also, the cured composition of the present invention, incombination with a suitable filler, and alternately, an additionalrubber and other components, may have a Tangent Delta (G″/G′) value at−30° C. of greater than 0.60 in one embodiment, and greater than 0.70 inanother embodiment, and greater than 0.80 in yet another embodiment, andfrom 0.50 to 1.2 in yet another embodiment, from 0.60 to 1.1 in yetanother embodiment, and from 0.70 to 1.1 in yet another embodiment. TheTangent Delta (G″/G′) value at 0° C. of the cured composition may begreater than 0.20 in one embodiment, and greater than 0.25 in anotherembodiment, and greater than 0.30 in yet another embodiment, and from0.20 to 0.80 in yet another embodiment, from 0.25 to 0.70 in yet anotherembodiment, and from 0.25 to 0.65 in yet another embodiment.Compositions of the terpolymer would be expected, based on the tangentdelta values at 60° C., to have a similar heat buildup relative to theother components of, for example, a tire. Thus, there would be nohysteresis expected in using the terpolymer of the present invention ininnerliners and innertubes.

[0113] The present invention includes the use of the terpolymerdescribed and characterized above in various compositions, and themethod of making the terpolymer and compositions. One embodiment of thepresent invention is an elastomeric composition suitable for an airbarrier comprising a filler; a sulfur cure system; and at least onehalogenated terpolymer of C₄ to C₈ isoolefin derived units, C₄ to C₁₄multiolefin derived units, and p-alkylstyrene derived units.

[0114] Alternatively, the present invention can be described as a curedelastomeric composition comprising at least one halogenated terpolymerof C₄ to C₈ isoolefin derived units, C₄ to C₁₄ multiolefin derivedunits, and p-alkylstyrene derived units, wherein the composition iscured in the presence of a sulfur cure system; and wherein the adhesionto SBR value at 100° C. of the cured composition is from greater than 70N/mm.

[0115] The elastomeric composition may include at least one metal oxide,elemental sulfur, and optionally at least one accelerator in oneembodiment.

[0116] The filler of the elastomeric composition may be selected fromcarbon black, silica, alumina, calcium carbonate, clay, mica, talc,titanium dioxide, starch, wood flower, and mixtures thereof in anotherembodiment.

[0117] The elastomeric composition may also include a secondary rubberin another embodiment, wherein the secondary rubber is selected fromnatural rubber, polybutadiene rubber, nitrile rubber, silicon rubber,polyisoprene rubber, poly(styrene-co-butadiene) rubber,poly(isoprene-co-butadiene) rubber, styrene-isoprene-butadiene rubber,ethylene-propylene rubber, brominated butyl rubber, chlorinated butylrubber, halogenated isoprene, halogenated isobutylene copolymers,polychloroprene, star-branched polyisobutylene rubber, star-branchedbrominated butyl rubber, poly(isobutylene-co-isoprene) rubber;halogenated poly(isobutylene-co-p-methylstyrene) and mixtures thereof.

[0118] In another embodiment of the elastomeric composition of theinvention, the C₄ to C₈ isoolefin monomer is isobutylene; and the C₄ toC₁₄ multiolefin monomer is isoprene in another embodiment; and thep-alkylstyrene is p-methylstyrene in yet another embodiment.

[0119] In yet another embodiment of the elastomeric composition, theterpolymer is brominated.

[0120] The bromine level of the terpolymer of the elastomericcomposition may be in the range of from 0.1 mole % to 2.5 mole % basedon the total moles of monomer derived units in the terpolymer in oneembodiment, and from 0.2 mole % to 2 mole % based on the total moles ofmonomer derived units in the terpolymer.

[0121] In yet another embodiment of the elastomeric composition, theterpolymer has a number average molecular weight of from 300,000 to800,000. In yet another embodiment, the filler is carbon black, or blendof carbon black and silica or an exfoliated clay in another embodiment.

[0122] The composition has certain desirable properties that make itsuitable for such articles as tire and shoe components, particularly inair barriers. In one embodiment, the adhesion to SBR value at 100° C. isgreater than 100 N/mm, and greater than 200 N/mm in another embodiment.

[0123] The elastomeric composition has a DIN Abrasion Index of greaterthan 45 units in one embodiment, and a tangent delta value of fromgreater than 0.60 at −30° C. in another embodiment and a tangent deltavalue of from greater than 0.20 at 0° C. in yet another embodiment. Theelastomeric composition is thus suitable for such articles as tireinnerliners and treads, sidewalls, etc.

[0124] The present invention also includes an improved method of makinga BrIBIMS terpolymer and compositions of the terpolymer. A method ofproducing an elastomeric terpolymer composition includes combining, in adiluent, C₄ to C₈ isoolefin monomers, C₄ to C₁₄ multiolefin monomers,and p-alkylstyrene monomers in the presence of a Lewis acid and at leastone initiator to produce the terpolymer.

[0125] In one embodiment of the method of making the terpolymer, theinitiator is described by the following formula:

[0126] wherein X is a halogen; R₁ is selected from hydrogen, C₁ to C₈alkyls, and C₂ to C₈ alkenyls, aryl, and substituted aryl; R₃ isselected from C₁ to C₈ alkyls, C₂ to C₈ alkenyls, aryls, and substitutedaryls; and R₂ is selected from C₄ to C₂₀₀ alkyls in one embodiment, andfrom C₄ to C₅₀ alkyls in another embodiment, C₂ to C₈ alkenyls, aryls,and substituted aryls, C₃ to C₁₀ cycloalkyls, and

[0127] wherein X is a halogen; R₅ is selected from C₁ to C₈ alkyls, andC₂ to C₈ alkenyls; R₆ is selected from C₁ to C₈ alkyls, C₂ to C₈alkenyls aryls, and substituted aryls; and R₄ is selected fromphenylene, biphenyl, α,ω-diphenylalkane and —(CH₂)_(n)—, wherein n is aninteger from 1 to 10; and wherein R₁, R₂, and R₃ can also form adamantylor bornyl ring systems.

[0128] In another embodiment of the method of making the terpolymer, theLewis acid is selected from of aryl aluminum halides, alkyl-substitutedaryl aluminum halides, alkyl aluminum halides and a mixture thereof.

[0129] The Lewis acid is selected from the group of dialkyl aluminumhalide, monoalkyl aluminum dihalide, aluminum tri-halide, ethylaluminumsesquichloride, and a mixture thereof in one embodiment, and is selectedfrom AlCl₃, EtAlCl₂, Et_(1.5)AlCl_(1.5), Et₂AlCl, and mixtures thereofin another embodiment.

[0130] In yet another embodiment of the method of making the terpolymerand composition, the dielectric constant of the diluent is greater than6 at 20° C., and greater than 9 at 20° C. in another embodiment. Inanother embodiment, the diluent is selected from methylcyclohexane,cyclohexane, toluene, carbon disulfide, ethyl chloride, methylchloride,methylene chloride, CHCl₃, CCl₄, n-butyl chloride, chlorobenzene, andmixtures thereof.

[0131] The method further includes the step of halogenating theterpolymer in another embodiment.

[0132] In another embodiment of the method of making the terpolymer, thetemperature for the polymerization is between −10° C. and the freezingpoint of the polymerization system.

[0133] While the present invention has been described and illustrated byreference to particular embodiments, those of ordinary skill in the artwill appreciate that the invention lends itself to many differentvariations not illustrated herein. For these reasons, then, referenceshould be made solely to the appended claims for purposes of determiningthe true scope of the present invention.

[0134] All priority documents are herein fully incorporated by referencefor all jurisdictions in which such incorporation is permitted. Further,all documents cited herein, including testing procedures, are hereinfully incorporated by reference for all jurisdictions in which suchincorporation is permitted. TABLE 1 Test Methods Parameter Units TestMooney Viscosity (BIMS polymer) ML 1 + 8, 125° C., MU ASTM D 1646(modified) Mooney Viscosity (composition) ML 1 + 4, 100° C., MU ASTM D1646 Brittleness ° C. ASTM D 746 Mooney Scorch Time T_(s)5, 125° C.,minutes ASTM D 1646 Moving Die Rheometer (MDR) @ 160° C., ±0.5° arc MLdNewton · m MH dNewton · m T_(s)2 minute T_(c)90 minute Cure rate dN ·m/minute ASTM D 2084 Physical Properties press cured Tc 90 + 2 min @160° C. Hardness Shore A ASTM D 2240 Modulus MPa ASTM D 412-68 TensileStrength MPa Elongation at Break % Rebound % Zwick 5901.01 ReboundTester ASTM D1054 or ISO 4662 or DIN 53512 Dispersion D scale —DisperGrader 1000 (Optigrade, Sweden) Abrasion Resistance (ARI) — ISO4649 or DIN 53516 Energy N/mm Area under the Elongation at break curve.Tangent Delta — Rheometrics ARES

[0135] TABLE 2 Components and Commercial Sources Component BriefDescription Commercial Source Budene ™ 1207 polybutadiene Goodyear(Akron, OH) BIIR 2222 brominated ExxonMobil Chemicalpoly(isobutylene-co- Company (Houston, TX) isoprene), Mooney viscosityof 40-60 MU (1 + 8, 125° C.), 2 wt % bromine CALSOL 810 processing oil;naphthenic R. E. Carroll (Trenton, NJ) oil EADC ethyl aluminumdichloride AKZO Nobel Chemical EXXPRO ™ 89-4 5 wt % PMS, 0.75 mol %ExxonMobil Chemical BrPMS, Mooney viscosity Company (Houston, TX) of 45± 5 MU (1 + 8, 125° C.) Isobutylene monomer ExxonMobil Chemical Company(Houston, TX) Isoprene monomer Aldrich Chemical Company MAGLITE-K cureagent, magnesium C. P. Hall (Chicago, IL) oxide MBTS 2,2′-benzothiazyldisulfide Sovereign Chemical Co. (Akron, OH) p-methylstyrene (PMS)monomer Aldrich Chemical Company SP-1068 brominated phenol- SchenectadyInternational formaldehyde resin (Schenectady, NY) SBB 6222star-branched butyl rubber; ExxonMobil Chemical 2 wt % Br Company(Houston, TX) STRUKTOL 40MS mixture of aliphatic, Struktol (Stow, OH)aromatic and naphthenic resins Stearic acid cure agent e.g., C. K. WitcoCorp. (Taft, LA) Sulfur cure agent e.g., R. E. Carroll (Trenton, NJ)zinc oxide, KADOX ™ 911 cure agent, zinc oxide Zinc Corp. of America(Monaca, PA)

[0136] TABLE 3 Reaction conditions and results for runs A-F to produceterpolymer using t-butylchloride as the initiator. Composite Condition AB C D E F (A-F) Moles monomer 0.390 0.390 0.390 0.390 0.390 0.390 —Volume Catalyst 48.0 66.0 75.5 50.0 51.5 65.5 — solution added (mL)†Change in 9.9 9.7 8.8 9.6 9.1 9.8 — temperature, ° C. Reaction time(min) 20.8 20.8 20.5 18.0 15.0 17.5 — % conversion 64.72 68.40 69.2461.64 58.68 59.68 — Mn 91,600 82,800 75,100 94,100 93,400 82,300 — Mw250,500 239,000 241,800 246,500 241,700 247,100 — Mp — 162,200 145,700168,900 175,900 158,900 — Mw/Mn 2.73 2.89 3.22 2.62 2.59 3.00 — Mole %unsaturated — — — — — — 4.14 groups (IP), H¹ NMR Mole % PMS in — — — — —— 4.64 interpolymer, H¹ NMR

[0137] TABLE 4 Components of examples¹ Component 3 (mol 7 (mol (phr) 1 2% Br) 4 5 6 % Br) SBB 6222 100 — — 100 — — — BIIR 2222 — — — — 100 — —IBMS — 100 — — — 100 — (EXXPRO 89-4) BrIBIMS — — 100 (0.86) — — — 100(1.1)

[0138] TABLE 5 Cure properties of examples property 1 2 3 4 5 6 7 MDR160° C., 0.5° arc ML, dN · m 1.12 1.86 0.51 1.22 1.33 1.53 0.48 MH, dN ·m 5.47 7.6 4.84 5.12 6.06 8.09 3.51 MH-ML, dN · m 4.35 5.74 4.33 3.94.73 6.56 3.03 Ts2, min 8.83 10.42 5.87 5.52 4.8 6.06 2.08 T50, min 9.3713.46 6.87 5.41 5.41 7.71 1.55 T90, min 16.66 24.96 22.91 10.28 12.1613.53 10.11

[0139] TABLE 6 Physical properties of examples property 1 2 3 4 5 6 7Mooney Viscosity, ML — — — 51.70 53.70 62.50 33.20 (1 + 4, 100° C.) 20%Modulus, MPa 0.58 0.65 0.58 0.57 0.53 0.68 0.64 100% Modulus, MPa 1.321.92 1.26 1.17 1.13 1.87 1.14 300% Modulus, MPa 4.40 5.85 3.81 3.65 3.685.72 3.01 Tensile, MPa 8.86 9.34 7.59 8.24 8.73 9.37 5.65 Elongation atBreak, % 693 658 754 730 754 720 787 Energy to Break, J 9.43 10.64 9.5610.53 12.00 13.18 8.73 Shore A Hardness at 23° C. 48.3 51.9 49.1 48.547.5 51.7 44.7 MOCON oxygen 9.789 8.534 9.673 11.6 11.0 9.9 10.7permeability (65° C.) (10⁸, cm³ · cm/cm² · sec · atm) Dispersion D scale5.6 6.9 6.3 5 6.2 7.2 6.6

[0140] TABLE 7 Aged properties of examples 4-7, and adhesion to SBRcarcass property 4 5 6 7 Rebound, % 10.2 10.2 9.9 8.8 Aging, 72 hrs @125° C. Aged 20% Modulus, 1.11 0.99 1.15 1.10 MPa Aged 100% Modulus,2.46 2.53 3.50 2.75 MPa Aged 300% Modulus, 6.20 6.60 8.75 6.30 MPa AgedTensile, MPa 7.15 8.11 10.42 6.88 Aged Elongation, % 391 525 467 380Aged energy to break, J 5.13 9.45 10.42 5.35 Adhesion to SBR 118.8 245.439.4 70.2 carcass @ 100° C., N/mm DIN Abrasion resistance 44 43 53 55Index Tear resistance, N/mm 3.54 7.89 1.29 1.79

[0141] TABLE 8 Representative Tangent Delta values for the elastomers inFIG. 1, examples 4-7 Tan Delta values at given temperatures, ° C. SBB(4) BIIR (5) BIMS (6) BrIBIMS (7) −30 0.849 0.915 1.007 0.980 0 0.3690.404 0.429 0.528 30 0.199 0.226 0.166 0.239 60 0.154 0.179 0.125 0.191

We claim:
 1. A cured elastomeric composition comprising a halogenatedterpolymer of C₄ to C₈ isoolefin derived units, C₄ to C₁₄ multiolefinderived units, and p-alkylstyrene derived units, wherein the compositionis cured in the presence of a sulfur cure system; and wherein theadhesion to SBR value at 100° C. of the cured composition is greaterthan 70 N/mm.
 2. The cured elastomeric composition of claim 1, alsocomprising a metal oxide, fatty acid, and an accelerator.
 3. The curedelastomeric composition of claim 1, also comprising a filler selectedfrom carbon black, modified carbon black, silica, alumina, calciumcarbonate, clay, mica, talc, titanium dioxide, starch, wood flower, andmixtures thereof.
 4. The cured elastomeric composition of claim 1, alsocomprising a secondary rubber selected from natural rubber,polybutadiene rubber, and mixtures thereof.
 5. The cured elastomericcomposition of claim 1, also comprising a secondary rubber selected fromnitrile rubber, silicon rubber, polyisoprene rubber,poly(styrene-co-butadiene) rubber, poly(isoprene-co-butadiene) rubber,styrene-isoprene-butadiene rubber, ethylene-propylene rubber, brominatedbutyl rubber, chlorinated butyl rubber, halogenated isoprene,halogenated isobutylene copolymers, polychloroprene, star-branchedpolyisobutylene rubber, star-branched brominated butyl rubber,poly(isobutylene-co-isoprene) rubber; halogenatedpoly(isobutylene-co-p-methylstyrene) and mixtures thereof.
 6. The curedelastomeric composition of claim 1, wherein the C₄ to C₈ isoolefin isisobutylene.
 7. The cured elastomeric composition of claim 1, whereinthe C₄ to C₁₄ multiolefin is selected from cyclopentadiene and isoprene.8. The cured elastomeric composition of claim 1, wherein thep-alkylstyrene is p-methylstyrene.
 9. The cured elastomeric compositionof claim 1, wherein the terpolymer is brominated.
 10. The curedelastomeric composition of claim 9, wherein the bromine is present inthe terpolymer in the range of from 0.1 mole % to 2.5 mole % based onthe total moles of monomer derived units in the terpolymer.
 11. Thecured elastomeric composition of claim 9, wherein the bromine is presentin the terpolymer in the range of from 0.2 mole % to 2 mole % based onthe total moles of monomer derived units in the terpolymer.
 12. Thecured elastomeric composition of claim 1, wherein the terpolymer has anumber average molecular weight of from 300,000 to 800,000.
 13. Thecured elastomeric composition of claim 1, wherein the adhesion to SBRvalue at 100° C. is greater than 100 N/mm.
 14. The cured elastomericcomposition of claim 1, wherein the adhesion to SBR value at 100° C. isgreater than 200 N/mm.
 15. The cured elastomeric composition of claim 1,also comprising carbon black.
 16. The cured elastomeric composition ofclaim 15, having a DIN Abrasion Index of greater than 45 units.
 17. Thecured elastomeric composition of claim 15, having a tangent delta valueof greater than 0.60 at −30° C.
 18. The cured elastomeric composition ofclaim 15, having a tangent delta value of greater than 0.20 at 0° C. 19.The cured elastomeric composition of claim 1, also comprising a fillerpresent from 5 to 100 phr.
 20. The elastomeric composition of claim 1,wherein the multiolefin derived units are present in the terpolymer from0.2 wt % to 30 wt % and the p-alkylstyrene derived units are presentfrom 0.5 wt % to 30 wt % by weight of the terpolymer.
 21. An innerlinercomprising the cured composition of claim
 1. 22. An innertube comprisingthe cured composition of claim
 1. 23. An elastomeric compositioncomprising a filler; a sulfur cure system; and a halogenated terpolymerof C₄ to C₈ isoolefin derived units, C₄ to C₁₄ multiolefin derivedunits, and p-alkylstyrene derived units.
 24. The elastomeric compositionof claim 23, also comprising a metal oxide, fatty acid, and anaccelerator.
 25. The elastomeric composition of claim 23, wherein thefiller is selected from carbon black, modified carbon black, silica,alumina, calcium carbonate, clay, mica, talc, titanium dioxide, starch,wood flower, and mixtures thereof.
 26. The elastomeric composition ofclaim 23, also comprising a secondary rubber selected from naturalrubber, polybutadiene rubber, and mixtures thereof.
 27. The elastomericcomposition of claim 23, also comprising a secondary rubber selectedfrom nitrile rubber, silicon rubber, polyisoprene rubber,poly(styrene-co-butadiene) rubber, poly(isoprene-co-butadiene) rubber,styrene-isoprene-butadiene rubber, ethylene-propylene rubber, brominatedbutyl rubber, chlorinated butyl rubber, halogenated isoprene,halogenated isobutylene copolymers, polychloroprene, star-branchedpolyisobutylene rubber, star-branched brominated butyl rubber,poly(isobutylene-co-isoprene) rubber; halogenatedpoly(isobutylene-co-p-methylstyrene) and mixtures thereof.
 28. Theelastomeric composition of claim 23, wherein the C₄ to C₈ isoolefin isisobutylene.
 29. The elastomeric composition of claim 23, wherein the C₄to C₁₄ multiolefin is selected from cyclopentadiene and isoprene. 30.The elastomeric composition of claim 23, wherein the p-alkylstyrene isp-methylstyrene.
 31. The elastomeric composition of claim 23, whereinthe terpolymer is brominated.
 32. The elastomeric composition of claim31, wherein the bromine is present in the terpolymer in the range offrom 0.1 mole % to 2.5 mole % based on the total moles of monomerderived units in the terpolymer.
 33. The elastomeric composition ofclaim 31, wherein the bromine is present in the terpolymer in the rangeof from 0.2 mole % to 2 mole % based on the total moles of monomerderived units in the terpolymer.
 34. The elastomeric composition ofclaim 23, wherein the terpolymer has a number average molecular weightof from 300,000 to 800,000.
 35. The elastomeric composition of claim 23,wherein the adhesion to SBR value at 100° C. of the cured composition isgreater than 70 N/mm.
 36. The elastomeric composition of claim 23,wherein the adhesion to SBR value at 100° C. of the cured composition isgreater than 100 N/mm.
 37. The elastomeric composition of claim 23,wherein the adhesion to SBR value at 100° C. of the cured composition isgreater than 200 N/mm.
 38. The elastomeric composition of claim 23,wherein the filler is carbon black.
 39. The elastomeric composition ofclaim 23, wherein the cured composition has a DIN Abrasion Index ofgreater than 45 units.
 40. The elastomeric composition of claim 23,wherein the cured composition has a tangent delta value of greater than0.60 at −30° C.
 41. The elastomeric composition of claim 23, wherein thecured composition has a tangent delta value of greater than 0.20 at 0°C.
 42. The elastomeric composition of claim 23, wherein the filler ispresent from 5 to 100 phr.
 43. The elastomeric composition of claim 23,wherein the multiolefin derived units are present in the terpolymer from0.2 wt % to 30 wt % and the p-alkylstyrene derived units are presentfrom 0.5 wt % to 30 wt % by weight of the terpolymer.
 44. An innerlinercomprising the composition of claim
 23. 45. An innertube comprising thecomposition of claim
 23. 46. An air barrier comprising the compositionof claim
 23. 47. An elastomeric composition comprising a sulfur curesystem; a halogenated terpolymer of C₄ to C₈ isoolefin derived units, C₄to C₁₄ multiolefin derived units, and p-alkylstyrene derived units; anda secondary rubber.
 48. The elastomeric composition of claim 47, alsocomprising a metal oxide, fatty acid, and an accelerator.
 49. Theelastomeric composition of claim 47, also comprising a filler selectedfrom modified carbon black, carbon black, silica, alumina, calciumcarbonate, clay, mica, talc, titanium dioxide, starch, wood flower, andmixtures thereof.
 50. The elastomeric composition of claim 47, whereinthe filler is carbon black.
 51. The elastomeric composition of claim 47,wherein the secondary rubber is selected from natural rubber,polybutadiene rubber, nitrile rubber, silicon rubber, polyisoprenerubber, poly(styrene-co-butadiene) rubber, poly(isoprene-co-butadiene)rubber, styrene-isoprene-butadiene rubber, ethylene-propylene rubber,brominated butyl rubber, chlorinated butyl rubber, halogenated isoprene,halogenated isobutylene copolymers, polychloroprene, star-branchedpolyisobutylene rubber, star-branched brominated butyl rubber,poly(isobutylene-co-isoprene) rubber; halogenatedpoly(isobutylene-co-p-methylstyrene) and mixtures thereof.
 52. Theelastomeric composition of claim 47, wherein the secondary rubber ispresent from 5 to 50 phr.
 53. The elastomeric composition of claim 47,wherein the C₄ to C₈ isoolefin monomer is isobutylene.
 54. Theelastomeric composition of claim 47, wherein the C₄ to C₁₄ multiolefinmonomer is isoprene.
 55. The elastomeric composition of claim 47,wherein the p-alkylstyrene is p-methylstyrene.
 56. The elastomericcomposition of claim 47, wherein the terpolymer is brominated.
 57. Theelastomeric composition of claim 47, wherein the halogen is present inthe terpolymer in the range of from 0.1 mole % to 2.5 mole % based onthe total moles of monomer derived units in the terpolymer.
 58. Theelastomeric composition of claim 47, wherein the halogen is present inthe terpolymer in the range of from 0.2 mole % to 2 mole % based on thetotal moles of monomer derived units in the terpolymer.
 59. Theelastomeric composition of claim 47, wherein the terpolymer has a numberaverage molecular weight of from 80,000 to 1,000,000.
 60. Theelastomeric composition of claim 47, wherein the terpolymer has a numberaverage molecular weight of from 300,000 to 800,000.
 61. The elastomericcomposition of claim 47, wherein the adhesion to SBR value at 100° C. isgreater than 70 N/mm.
 62. The elastomeric composition of claim 47,wherein the adhesion to SBR value at 100° C. is greater than 100 N/mm.63. The elastomeric composition of claim 47, wherein the adhesion to SBRvalue at 100° C. is greater than 200 N/mm.
 64. The elastomericcomposition of claim 47, wherein the filler is carbon black and theterpolymer is brominated.
 65. The elastomeric composition of claim 47,having a DIN Abrasion Index of greater than 90 units.
 66. Theelastomeric composition of claim 47, having a tangent delta value offrom greater than 0.60 at −30° C.
 67. The elastomeric composition ofclaim 47, having a tangent delta value of from greater than 0.25 at 0°C.
 68. The elastomeric composition of claim 47, wherein the filler ispresent from 10 to 100 phr.
 69. The elastomeric composition of claim 47,wherein the filler is present from 40 to 80 phr.
 70. An innerlinercomprising the composition of claim
 47. 71. An air barrier comprisingthe composition of claim
 47. 72. An innertube comprising the compositionof claim
 47. 73. An air barrier comprising a filler; a sulfur curesystem; and a halogenated terpolymer of C₄ to C₈ isoolefin derivedunits, C₄ to C₁₄ multiolefin derived units, and p-alkylstyrene derivedunits; wherein the DIN Abrasion Index of the air barrier is greater than50 units.
 74. The air barrier of claim 73, also comprising a metaloxide, fatty acid, and an accelerator.
 75. The air barrier of claim 73,wherein the filler is selected from carbon black, modified carbon black,silica, alumina, calcium carbonate, clay, mica, talc, titanium dioxide,starch, wood flower, and mixtures thereof.
 76. The air barrier of claim73, also comprising a secondary rubber selected from natural rubber,polybutadiene rubber, nitrile rubber, silicon rubber, polyisoprenerubber, poly(styrene-co-butadiene) rubber, poly(isoprene-co-butadiene)rubber, styrene-isoprene-butadiene rubber, ethylene-propylene rubber,brominated butyl rubber, chlorinated butyl rubber, halogenated isoprene,halogenated isobutylene copolymers, polychloroprene, star-branchedpolyisobutylene rubber, star-branched brominated butyl rubber,poly(isobutylene-co-isoprene) rubber; halogenatedpoly(isobutylene-co-p-methylstyrene) and mixtures thereof.
 77. The airbarrier of claim 73, wherein the C₄ to C₈ isoolefin monomer isisobutylene.
 78. The air barrier of claim 73, wherein the C₄ to C₁₄multiolefin monomer is selected from cyclopentadiene and isoprene. 79.The air barrier of claim 73, wherein the p-alkylstyrene isp-methylstyrene.
 80. The air barrier of claim 73, wherein the terpolymeris brominated.
 81. The air barrier of claim 80, wherein the bromine ispresent in the terpolymer in the range of from 0.1 mole % to 2.5 mole %based on the total moles of monomer derived units in the terpolymer. 82.The air barrier of claim 80, wherein the bromine is present in theterpolymer in the range of from 0.2 mole % to 2 mole % based on thetotal moles of monomer derived units in the terpolymer.
 83. The airbarrier of claim 73, wherein the terpolymer has a number averagemolecular weight of from 80,000 to 1,000,000.
 84. The air barrier ofclaim 73, wherein the terpolymer has a number average molecular weightof from 300,000 to 800,000.
 85. The air barrier of claim 73, wherein theadhesion to SBR value at 100° C. is greater than 100 N/mm.
 86. The airbarrier of claim 73, wherein the adhesion to SBR value at 100° C. isgreater than 200 N/mm.
 87. The air barrier of claim 73, wherein thefiller is carbon black.
 88. The air barrier of claim 73, having a DINAbrasion Index of greater than 50 units.
 89. The air barrier of claim73, having a tangent delta value of from greater than 0.60 at −30° C.90. The air barrier of claim 73, having a tangent delta value of fromgreater than 0.20 at 0° C.
 91. The air barrier of claim 73, wherein thefiller is present from 5 to 100 phr.
 92. The air barrier of claim 73,wherein the multiolefin derived units are present in the terpolymer from0.2 wt % to 30 wt % and the p-alkylstyrene derived units are presentfrom 0.5 wt % to 30 wt % by weight of the terpolymer.
 93. An innerlinerfor an automotive tire comprising the air barrier of claim
 73. 94. Aninnertube comprising the air barrier of claim
 73. 95. A method ofproducing an elastomeric terpolymer composition comprising combining, ina diluent, C₄ to C₈ isoolefin monomers, C₄ to C₁₄ multiolefin monomers,and p-alkylstyrene monomers in the presence of a Lewis acid and aninitiator to produce the terpolymer.
 96. The method of claim 95, whereinthe initiator is described by the following formula:

wherein X is a halogen; R₁ is selected from hydrogen, C₁ to C₈ alkyls,and C₂ to C₈ alkenyls, aryl, and substituted aryl; R₃ is selected fromC₁ to C₈ alkyls, C₂ to C₈ alkenyls, aryls, and substituted aryls; and R₂is selected from C₄ to C₂₀₀ alkyls, C₂ to C₈ alkenyls, aryls, andsubstituted aryls, C₃ to C₁₀ cycloalkyls, and

wherein X is a halogen; R₅ is selected from C₁ to C₈ alkyls, and C₂ toC₈ alkenyls; R₆ is selected from C₁ to C₈ alkyls, C₂ to C₈ alkenylsaryls, and substituted aryls; and R₄ is selected from phenylene,biphenyl, α,ω-diphenylalkane and —(CH₂)_(n)—, wherein n is an integerfrom 1 to 10; and wherein R₁, R₂, and R₃ can also form adamantyl orbornyl ring systems.
 97. The method of claim 95, wherein the Lewis acidis selected from of aryl aluminum halides, alkyl-substituted arylaluminum halides, alkyl aluminum halides and a mixture thereof.
 98. Themethod of claim 95, wherein the Lewis acid is selected from of dialkylaluminum halide, monoalkyl aluminum dihalide, aluminum tri-halide,ethylaluminum sesquichloride, and a mixture thereof.
 99. The method ofclaim 95, wherein the Lewis acid is selected from AlCl₃, EtAlCl₂,Et_(1.5)AlCl_(1.5), Et₂AlCl, and mixtures thereof.
 100. The method ofclaim 95, wherein the dielectric constant of the diluent is greater than6 at 20° C.
 101. The method of claim 95, wherein the dielectric constantof the diluent is greater than 9 at 20° C.
 102. The method of claim 95,wherein the diluent is selected from methylcyclohexane, cyclohexane,toluene, carbon disulfide, ethyl chloride, methylchloride, methylenechloride, CHCl₃, CCl₄, n-butyl chloride, chlorobenzene, and mixturesthereof.
 103. The method of claim 95, further including the step ofhalogerrating the terpolymer.
 104. The method of claim 95, wherein thehalogen is present in the terpolymer in the range of from 0.1 mole % to2.5 mole % based on the total moles of monomer derived units in theterpolymer.
 105. The method of claim 95, wherein the halogen is presentin the terpolymer in the range of from 0.2 mole % to 2 mole % based onthe total moles of monomer derived units in the terpolymer.
 106. Themethod of claim 95, further comprising combining a metal oxide, fattyacid, and a sulfur based accelerator.
 107. The method of claim 95,further comprising combining a filler selected from modified carbonblack, carbon black, silica, alumina, calcium carbonate, clay, mica,talc, titanium dioxide, starch, wood flower, and mixtures thereof. 108.The method of claim 95, wherein the filler is carbon black.
 109. Themethod of claim 95, further comprising combining a secondary rubberselected from natural rubber and polybutadiene rubber, nitrile rubber,silicon rubber, polyisoprene rubber, styrene-butadiene rubber,isoprene-butadiene rubber, styrene-isoprene-butadiene rubber,ethylene-propylene rubber, brominated butyl rubber, chlorinated butylrubber, halogenated isoprene, halogenated isobutylene copolymers,polychloroprene, star-branched polyisobutylene rubber, star-branchedbrominated butyl rubber, polyisobutylene-isoprene rubber; halogenatedpoly(isobutylene-co-p-methylstyrene) and mixtures thereof.